diff --git a/services/nginx/app/modules/selfserve/interfaces/selfserve_wash_flow_i.php b/services/nginx/app/modules/selfserve/interfaces/selfserve_wash_flow_i.php
index d4021f22..fd62d696 100644
--- a/services/nginx/app/modules/selfserve/interfaces/selfserve_wash_flow_i.php
+++ b/services/nginx/app/modules/selfserve/interfaces/selfserve_wash_flow_i.php
@@ -14,7 +14,7 @@ interface selfserve_wash_flow_i
 
     public function getLatestSessionSummary(int $laneId, string $reg): array;
 
-    public function completeLatestSessionForLane(int $laneId, ?string $reg = null, ?int $customerNumber = null, ?int $orderId = null, bool $disableRelays = true): ?array;
+    public function completeLatestSessionForLane(int $laneId, ?string $reg = null, ?int $customerNumber = null, ?int $orderId = null, bool $disableRelays = true, ?int $subuserId = null): ?array;
 
     public function forceStopLane(int $laneId, ?int $sessionId = null, bool $bill = false, ?string $reason = null, ?int $userId = null): array;
 }
diff --git a/services/nginx/app/modules/selfserve/selfserve.md b/services/nginx/app/modules/selfserve/selfserve.md
index 442a3822..649fbd8c 100644
--- a/services/nginx/app/modules/selfserve/selfserve.md
+++ b/services/nginx/app/modules/selfserve/selfserve.md
@@ -356,8 +356,8 @@ Purpose: operational lane control and relay management.
 | Method | Required params | Permissions | Notes |
 | --- | --- | --- | --- |
 | `GET /modules/self-serve/lane/status` | optional `lane_id`, default `1` | `modules_selfserve_lane_status_view` | Returns lane status, mode, state, wash timer, reg, and customer number. |
-| `POST /modules/self-serve/lane/command` | `lane_id`, `command` | `modules_selfserve_lane_command_execute` plus command-specific permission, or customer `list_own_department_selfserve_vehicle_conditions` for scoped `START`, scoped `STOP`, and property gate commands | Valid commands: `START`, `STOP`, `RESET`, `RESERVE`, `RELEASE`, `OPEN_PROPERTY_ACCESS_GATE`, `OPEN_PROPERTY_EXIT_GATE`. Customer `START` requires an enabled self-serve lane. Customer `STOP` and property gate commands require the customer's active wash in the lane department. |
-| `POST /modules/self-serve/lane/services/allowed` | `lane_id`, optional `task_ids` | `modules_selfserve_lane_services_set_allowed`, or customer `list_own_department_selfserve_vehicle_conditions` on an enabled self-serve lane | Writes allowed service names to the lane cache. This is still read-from-visible-tasks only; it does not activate relays. |
+| `POST /modules/self-serve/lane/command` | `lane_id`, `command` | `modules_selfserve_lane_command_execute` plus command-specific permission, customer `add_own_department_selfserve_vehicle_conditions` for scoped `START`, or customer `list_own_department_selfserve_vehicle_conditions` for scoped `STOP` and property gate commands | Valid commands: `START`, `STOP`, `RESET`, `RESERVE`, `RELEASE`, `OPEN_PROPERTY_ACCESS_GATE`, `OPEN_PROPERTY_EXIT_GATE`. Customer `START` requires an enabled self-serve lane. Customer `STOP` and property gate commands require the customer's active wash in the lane department. |
+| `POST /modules/self-serve/lane/services/allowed` | `lane_id`, optional `task_ids` | `modules_selfserve_lane_services_set_allowed`, or customer `add_own_department_selfserve_vehicle_conditions` on an enabled self-serve lane | Writes allowed service names to the lane cache. This is still read-from-visible-tasks only; it does not activate relays. |
 | `GET /modules/self-serve/lane/relay/machine_program_picker/status` | `lane_id` | `modules_selfserve_lane_relay_machine_program_picker_status_view` | Reads the Shelly MACHINE_PROGRAM_PICKER relay state (`on`/`off`) for the lane. |
 | `POST /modules/self-serve/lane/relay/machine_program_picker/set` | `lane_id`, `on` | `modules_selfserve_lane_relay_machine_program_picker_status_set` | Sets Shelly MACHINE_PROGRAM_PICKER relay state directly (`on=true/false`) and returns updated status. |
 | `GET /modules/self-serve/lane/relay/machine_cleaner/status` | `lane_id` | `modules_selfserve_lane_relay_machine_cleaner_status_view` | Reads the Shelly MACHINE_CLEANER relay state (`on`/`off`) for the lane. |
@@ -439,7 +439,7 @@ Public methods:
 | `recordMachineStartWebhook(int $laneId, ?string $reg = null, array $payload = [])` | The machine button or hardware event fired. | Full session summary after the machine-start event. |
 | `getSessionSummary(int $sessionId)` | You have a session id already. | Full session summary. |
 | `getLatestSessionSummary(int $laneId, string $reg)` | You want the latest session for a lane and vehicle. | Full session summary. |
-| `completeLatestSessionForLane(int $laneId, ?string $reg = null, ?int $customerNumber = null, ?int $orderId = null, bool $disableRelays = true)` | STOP has finished and you want to close the latest open session. Normal STOP passes `false` because it already disabled relays before opening the exit port. | Full summary, or `null` if no open session exists. |
+| `completeLatestSessionForLane(int $laneId, ?string $reg = null, ?int $customerNumber = null, ?int $orderId = null, bool $disableRelays = true, ?int $subuserId = null)` | STOP has finished and you want to close the latest open session. Normal STOP passes `false` because it already disabled relays before opening the exit port. Driver flows pass `subuserId` so same-customer drivers close only their own session. | Full summary, or `null` if no open session exists. |
 
 Key implementation details:
 
diff --git a/services/nginx/app/modules/selfserve/traits/selfserve_lane_command_t.php b/services/nginx/app/modules/selfserve/traits/selfserve_lane_command_t.php
index eca32e5b..bd1161bc 100644
--- a/services/nginx/app/modules/selfserve/traits/selfserve_lane_command_t.php
+++ b/services/nginx/app/modules/selfserve/traits/selfserve_lane_command_t.php
@@ -120,14 +120,15 @@ trait selfserve_lane_command_t
     /**
      * Machine-wash billing is based on the physical machine ON signal, not selector relay status.
      */
-    protected function hasMachineStartSignalForStop(): bool
+    protected function hasMachineStartSignalForStop(?int $subuser_id = null): bool
     {
         try {
             $customerNumber = method_exists($this, 'getCustomerNumber') ? (int)$this->getCustomerNumber() : null;
             return (new selfserve_wash_flow())->hasMachineStartTriggeredForLane(
                 (int)$this->id,
                 method_exists($this, 'getLicensePlate') ? ($this->getLicensePlate() ?: null) : null,
-                $customerNumber !== null && $customerNumber > 0 ? $customerNumber : null
+                $customerNumber !== null && $customerNumber > 0 ? $customerNumber : null,
+                $subuser_id
             );
         } catch (\Throwable) {
             return false;
@@ -240,7 +241,9 @@ trait selfserve_lane_command_t
             $snapshot = (new selfserve_wash_flow())->previewVehicleEligibility(
                 (int)$this->id,
                 $reg,
-                $customerNumber !== null && $customerNumber > 0 ? $customerNumber : null
+                $customerNumber !== null && $customerNumber > 0 ? $customerNumber : null,
+                null,
+                ['subuser_id' => $arguments?->subuser_id]
             );
 
             return (bool)($snapshot['allowed'] ?? false);
@@ -531,7 +534,7 @@ trait selfserve_lane_command_t
     /**
      * Finalize any active self-serve wash session before resetting lane state.
      */
-    protected function completeLatestSessionForStop(): void
+    protected function completeLatestSessionForStop(?int $subuser_id = null): void
     {
         try {
             (new \modules\selfserve\classes\selfserve_wash_flow())->completeLatestSessionForLane(
@@ -539,7 +542,8 @@ trait selfserve_lane_command_t
                 $this->getLicensePlate() ?: null,
                 $this->getCustomerNumber() ?: null,
                 method_exists($this, 'getLastInvoiceOrderId') ? $this->getLastInvoiceOrderId() : null,
-                false
+                false,
+                $subuser_id
             );
         } catch (\Throwable) {
             // Session completion must not block STOP flow.
@@ -711,7 +715,7 @@ trait selfserve_lane_command_t
                     throw new \InvalidArgumentException("Customer number mismatch: Lane customer number " . $this->getCustomerNumber() . " does not match argument customer number " . $arguments->customer_number);
                 }
                 // Snapshot the physical machine ON signal before session completion/reset.
-                $machine_start_triggered = $this->hasMachineStartSignalForStop();
+                $machine_start_triggered = $this->hasMachineStartSignalForStop($arguments->subuser_id);
                 // Turn off relays before any configured or default exit gate opens.
                 $this->turnOffRelaysAfterStop();
                 $this->runPublishedStudioActions(
@@ -733,7 +737,7 @@ trait selfserve_lane_command_t
                 // Only bill the machine wash product when the physical machine start signal was recorded.
                 $this->addVehicleTypeProductToInvoiceIfNeeded($machine_start_triggered);
                 // Finalize any active self-serve wash session for this lane
-                $this->completeLatestSessionForStop();
+                $this->completeLatestSessionForStop($arguments->subuser_id);
                 // Reset the lane
                 self::execute(selfserve_lane_command::RESET, new selfserve_lane_command_arguments());
                 break;
diff --git a/services/nginx/app/modules/selfserve/traits/selfserve_lane_invoice_t.php b/services/nginx/app/modules/selfserve/traits/selfserve_lane_invoice_t.php
index 28f0b7b1..3d004a84 100644
--- a/services/nginx/app/modules/selfserve/traits/selfserve_lane_invoice_t.php
+++ b/services/nginx/app/modules/selfserve/traits/selfserve_lane_invoice_t.php
@@ -260,8 +260,9 @@ trait selfserve_lane_invoice_t
         ?int $draft_customer_number,
         ?selfserve_lane_command_arguments $arguments = null
     ): array {
-        $session = $this->findOpenSelfServeSessionForAttachment($billing_customer_number);
-        $subuser_id = $arguments?->subuser_id;
+        $session = $this->findOpenSelfServeSessionForAttachment($billing_customer_number, $arguments?->subuser_id);
+        $session_subuser_id = $session?->subuser_id->value() === null ? null : (int)$session->subuser_id->value();
+        $subuser_id = $arguments?->subuser_id ?? $session_subuser_id;
 
         return [
             'type' => attachment_content::OTHER_TYPE_SELF_SERVE_WASH,
@@ -282,7 +283,7 @@ trait selfserve_lane_invoice_t
         ];
     }
 
-    protected function findOpenSelfServeSessionForAttachment(int $billing_customer_number): ?selfserve_wash_sessions_o
+    protected function findOpenSelfServeSessionForAttachment(int $billing_customer_number, ?int $subuser_id = null): ?selfserve_wash_sessions_o
     {
         $license_plate = trim((string)$this->getLicensePlate());
         if ($license_plate === '') {
@@ -293,7 +294,8 @@ trait selfserve_lane_invoice_t
             $session = (new selfserve_wash_sessions_o())->selectLatestOpenByLaneAndReg(
                 (int)$this->id,
                 selfserve::standardize_registration($license_plate),
-                $billing_customer_number > 0 ? $billing_customer_number : null
+                $billing_customer_number > 0 ? $billing_customer_number : null,
+                $subuser_id
             );
             return $session->exists() ? $session : null;
         } catch (\Throwable) {
diff --git a/services/nginx/app/openapi.yaml b/services/nginx/app/openapi.yaml
index 6db7b732..051ab108 100644
--- a/services/nginx/app/openapi.yaml
+++ b/services/nginx/app/openapi.yaml
@@ -9851,6 +9851,9 @@ paths:
                       customer_number:
                         type: integer
                         nullable: true
+                      subuser_id:
+                        type: integer
+                        nullable: true
                       vehicle_id:
                         type: integer
                         nullable: true
@@ -9903,6 +9906,18 @@ paths:
                       phone:
                         type: string
                         nullable: true
+                  subuser:
+                    type: object
+                    nullable: true
+                    properties:
+                      id:
+                        type: integer
+                      name:
+                        type: string
+                        nullable: true
+                      username:
+                        type: string
+                        nullable: true
                   vehicle:
                     type: object
                     nullable: true
@@ -9930,7 +9945,8 @@ paths:
       summary: Get the authenticated customer's active self-serve wash
       description: |
         Returns the latest active self-serve wash for the authenticated customer,
-        without requiring the frontend to know or poll a lane id.
+        without requiring the frontend to know or poll a lane id. Driver sessions
+        are scoped to the authenticated subuser under the selected customer number.
       operationId: getMyActiveSelfServeWash
       responses:
         '200':
@@ -9951,9 +9967,16 @@ paths:
                   session:
                     type: object
                     nullable: true
+                    properties:
+                      subuser_id:
+                        type: integer
+                        nullable: true
                   customer:
                     type: object
                     nullable: true
+                  subuser:
+                    type: object
+                    nullable: true
                   vehicle:
                     type: object
                     nullable: true
@@ -10088,8 +10111,9 @@ paths:
         Property gate commands (`OPEN_PROPERTY_ACCESS_GATE`, `OPEN_PROPERTY_EXIT_GATE`) are also supported here.
         Property gate commands require the matching explicit command permissions.
         Operator callers require the base command permission plus the command-specific permission. Authenticated
-        customers with `list_own_department_selfserve_vehicle_conditions` may send `START` on enabled self-serve
-        lanes. Customer `STOP` requires the customer's active self-serve wash in the target department.
+        customers with `add_own_department_selfserve_vehicle_conditions` may send `START` on enabled self-serve
+        lanes. Customer `STOP` requires `list_own_department_selfserve_vehicle_conditions` and the customer's active
+        self-serve wash in the target department.
       operationId: sendSelfServeLaneCommand
       requestBody:
         required: true
@@ -10156,7 +10180,7 @@ paths:
         derived from the tasks currently shown to the user after answering the self-serve questions.
         This endpoint does not activate anything by itself; it only sets what is allowed to be activated.
         Operator callers require `modules_selfserve_lane_services_set_allowed`; authenticated customers with
-        `list_own_department_selfserve_vehicle_conditions` may update their enabled self-serve lane before
+        `add_own_department_selfserve_vehicle_conditions` may update their enabled self-serve lane before
         confirming a wash start.
       operationId: setSelfServeLaneAllowedServices
       requestBody:
diff --git a/services/nginx/app/routes/departmentSelfserveVehicleConditionsRoute.php b/services/nginx/app/routes/departmentSelfserveVehicleConditionsRoute.php
index 8797bcc9..59ad408e 100644
--- a/services/nginx/app/routes/departmentSelfserveVehicleConditionsRoute.php
+++ b/services/nginx/app/routes/departmentSelfserveVehicleConditionsRoute.php
@@ -119,7 +119,7 @@ class departmentSelfserveVehicleConditionsRoute
          */
         $this->get('/department/selfserve/vehicle/allowed', function () {
             global $response;
-            [$user, $actor_id] = $this->getAuthenticatedSelfServePrincipal();
+            [$user, $actor_id, $subuser_id] = $this->getAuthenticatedSelfServePrincipal();
             $own_permission = self::definePermission('list_own_department_selfserve_vehicle_conditions', subusers_permission_node_key::SELFSERVE_LIST);
 
             $has_global = $user !== null && $this->hasPermission('list_department_selfserve_vehicle_conditions');
@@ -147,11 +147,14 @@ class departmentSelfserveVehicleConditionsRoute
             if ($vehicle_type_id !== null) {
                 $flow->synchronizeSession($lane_id, $reg, $customer_number, false, $vehicle_type_id, false, [
                     'create_session' => false,
+                    'subuser_id' => $subuser_id,
                 ]);
             }
 
             (new logs_o())->add('department_selfserve_vehicle_conditions', (int)$lane->department->value(), 1, $actor_id, 'CHECK_VEHICLE_ALLOWED', 'User checked self-serve eligibility for lane ' . $lane_id . ' and vehicle ' . $reg);
-            $response->success($flow->previewVehicleEligibility($lane_id, $reg, $customer_number, $vehicle_type_id));
+            $response->success($flow->previewVehicleEligibility($lane_id, $reg, $customer_number, $vehicle_type_id, [
+                'subuser_id' => $subuser_id,
+            ]));
         }, [
             'list_department_selfserve_vehicle_conditions' => 'Check whether self-serve is allowed for a specific vehicle',
             'list_own_department_selfserve_vehicle_conditions' => 'Check whether self-serve is allowed for a customer-scoped vehicle'
@@ -162,7 +165,7 @@ class departmentSelfserveVehicleConditionsRoute
          */
         $this->get('/department/selfserve/washes/summary', function () {
             global $response;
-            [$user] = $this->getAuthenticatedSelfServePrincipal();
+            [$user, $_actor_id, $subuser_id] = $this->getAuthenticatedSelfServePrincipal();
             $own_permission = self::definePermission('list_own_department_selfserve_vehicle_conditions', subusers_permission_node_key::SELFSERVE_LIST);
 
             $has_global = $user !== null && $this->hasPermission('list_department_selfserve_vehicle_conditions');
@@ -192,7 +195,10 @@ class departmentSelfserveVehicleConditionsRoute
                             false,
                             $vehicle_type_id,
                             false,
-                            ['create_session' => false]
+                            [
+                                'create_session' => false,
+                                'subuser_id' => $subuser_id,
+                            ]
                         );
                         if (!empty($refreshed_summary['session']['id'])) {
                             $summary = $refreshed_summary;
@@ -215,6 +221,7 @@ class departmentSelfserveVehicleConditionsRoute
                 if ($vehicle_type_id !== null) {
                     $summary = $flow->synchronizeSession($lane_id, $reg, $customer_number, false, $vehicle_type_id, false, [
                         'create_session' => false,
+                        'subuser_id' => $subuser_id,
                     ]);
                     if (empty($summary['session']['id'])) {
                         try {
@@ -241,7 +248,7 @@ class departmentSelfserveVehicleConditionsRoute
          */
         $this->post('/department/selfserve/vehicle/conditions', function () {
             global $response;
-            [$user, $actor_id] = $this->getAuthenticatedSelfServePrincipal();
+            [$user, $actor_id, $subuser_id] = $this->getAuthenticatedSelfServePrincipal();
             $own_permission = self::definePermission('add_own_department_selfserve_vehicle_conditions', subusers_permission_node_key::SELFSERVE_ADD);
 
             $has_global = $user !== null && $this->hasPermission('add_department_selfserve_vehicle_conditions');
@@ -281,7 +288,9 @@ class departmentSelfserveVehicleConditionsRoute
             try {
                 $condition_o = new department_selfserve_vehicle_conditions_o();
                 $condition_o->add($department, $lane, $reg, $question, $value, $customer_id);
-                $summary = $this->getWashFlow()->synchronizeSession($lane, $reg, $customer_id, $activate_machine, $vehicle_type_id, $sync_relay_state);
+                $summary = $this->getWashFlow()->synchronizeSession($lane, $reg, $customer_id, $activate_machine, $vehicle_type_id, $sync_relay_state, [
+                    'subuser_id' => $subuser_id,
+                ]);
                 (new logs_o())->add('department_selfserve_vehicle_conditions', 'global', 1, $actor_id, 'ADD_VEHICLE_CONDITION', 'User added department self-serve vehicle condition ' . $condition_o->id);
                 $response->success([
                     'condition' => $condition_o->asArray(),
@@ -469,12 +478,12 @@ class departmentSelfserveVehicleConditionsRoute
         $auth = new authentication();
         $user = $auth->get_user();
         if ($user !== false) {
-            return [$user, (int)$user->id];
+            return [$user, (int)$user->id, null];
         }
 
         $subuser = $auth->get_subuser();
         if ($subuser !== false) {
-            return [null, (int)$subuser->id];
+            return [null, (int)$subuser->id, (int)$subuser->id];
         }
 
         $response->error('Invalid session', 400);
diff --git a/services/nginx/app/routes/moduleSelfServeRoute.php b/services/nginx/app/routes/moduleSelfServeRoute.php
index e010d37d..4fd4c113 100644
--- a/services/nginx/app/routes/moduleSelfServeRoute.php
+++ b/services/nginx/app/routes/moduleSelfServeRoute.php
@@ -29,6 +29,7 @@ use objects\customer_vehicles_o;
 use objects\selfserve_wash_sessions_o;
 use objects\selfserve_wash_session_tasks_o;
 use objects\stripe_module_customers_o;
+use objects\subusers_o;
 use objects\users_o;
 use traits\route_t;
 
@@ -38,6 +39,7 @@ class moduleSelfServeRoute
 
     private const MAX_GATE_OPEN_TOGGLE_AFTER_SECONDS = 5;
     private const CUSTOMER_SELFSERVE_PERMISSION = 'list_own_department_selfserve_vehicle_conditions';
+    private const CUSTOMER_SELFSERVE_USE_PERMISSION = 'add_own_department_selfserve_vehicle_conditions';
 
     public function run(): void
     {
@@ -262,6 +264,7 @@ class moduleSelfServeRoute
                         'status' => $lane_state->name,
                         'reg' => $runtime_reg,
                         'customer_number' => $runtime_customer_number,
+                        'subuser_id' => null,
                         'vehicle_id' => $vehicle['id'] ?? null,
                         'vehicle_type_id' => $vehicle['type'] ?? null,
                         'included_minutes' => $included_minutes,
@@ -273,14 +276,16 @@ class moduleSelfServeRoute
                         'wash_started_at' => $wash_started_at,
                         'created_at' => null,
                         'updated_at' => null,
-                    ],
-                    'customer' => $customer,
-                    'vehicle' => $vehicle,
-                ], $customer_scope));
+                ],
+                'customer' => $customer,
+                'subuser' => null,
+                'vehicle' => $vehicle,
+            ], $customer_scope));
                 return;
             }
 
             $customer_number = $session->customer_number->value() === null ? null : (int)$session->customer_number->value();
+            $subuser_id = $session->subuser_id->value() === null ? null : (int)$session->subuser_id->value();
             $vehicle_id = $session->vehicle_id->value() === null ? null : (int)$session->vehicle_id->value();
             $session_reg = trim((string)$session->reg->value());
             if ($session_reg === '') {
@@ -318,6 +323,7 @@ class moduleSelfServeRoute
                     'status' => (string)$session->status->value(),
                     'reg' => $session_reg,
                     'customer_number' => $customer_number,
+                    'subuser_id' => $subuser_id,
                     'vehicle_id' => $vehicle_id,
                     'vehicle_type_id' => $session->vehicle_type_id->value() === null ? null : (int)$session->vehicle_type_id->value(),
                     'included_minutes' => $included_minutes ?? 0,
@@ -331,12 +337,13 @@ class moduleSelfServeRoute
                     'updated_at' => $session->updated_at->value() === null ? null : (string)$session->updated_at->value(),
                 ],
                 'customer' => $customer,
+                'subuser' => $this->buildInProgressWashSubuserPayload($subuser_id),
                 'vehicle' => $vehicle,
             ], $customer_scope));
         },
             [
                 'modules_selfserve_lane_wash_in_progress_view' => 'View customer and vehicle details for an in-progress self-serve wash on a lane',
-                'list_own_department_selfserve_vehicle_conditions' => 'View in-progress self-serve wash details for the authenticated customer',
+                'add_own_department_selfserve_vehicle_conditions' => 'Use in-progress self-serve wash details for the authenticated customer',
             ]
         );
 
@@ -344,8 +351,11 @@ class moduleSelfServeRoute
         $this->get('/modules/self-serve/lane/wash/my-active-wash', function () {
             global $response;
 
-            $customer_number = $this->requireMyActiveWashCustomerNumber();
-            $session = $this->findLatestActiveSelfServeSessionForCustomer($customer_number);
+            $principal_scope = $this->requireMyActiveWashPrincipalScope();
+            $session = $this->findLatestActiveSelfServeSessionForCustomer(
+                (int)$principal_scope['customer_number'],
+                $principal_scope['subuser_id']
+            );
             if (!$session->exists()) {
                 $response->error('No active self-serve wash found.', 404);
             }
@@ -353,7 +363,7 @@ class moduleSelfServeRoute
             $response->success($this->buildActiveSelfServeSessionResponse($session));
         },
             [
-                'list_own_department_selfserve_vehicle_conditions' => 'View the authenticated customer\'s active self-serve wash',
+                'add_own_department_selfserve_vehicle_conditions' => 'Use the authenticated customer\'s active self-serve wash',
             ]
         );
 
@@ -369,6 +379,7 @@ class moduleSelfServeRoute
                 'department_id',
                 'machine_type_id',
                 'customer_number',
+                'subuser_id',
                 'vehicle_id',
                 'vehicle_type_id',
                 'reg',
@@ -392,6 +403,9 @@ class moduleSelfServeRoute
 
                     return [
                         ...$session->asArray(),
+                        'subuser' => $this->buildInProgressWashSubuserPayload(
+                            $session->subuser_id->value() === null ? null : (int)$session->subuser_id->value()
+                        ),
                         'elapsed_minutes' => $session->getElapsedMinutes(),
                         'open' => $session->isOpen(),
                     ];
@@ -585,7 +599,8 @@ class moduleSelfServeRoute
                                 $customer_number > 0 ? $customer_number : null,
                                 false,
                                 null,
-                                false
+                                false,
+                                ['subuser_id' => $args->subuser_id]
                             );
                         }
                     } catch (\Throwable $e) {
@@ -1421,7 +1436,7 @@ class moduleSelfServeRoute
         ]);
     }
 
-    private function requireInProgressWashDetailsAccess(int $lane_id): ?int
+    private function requireInProgressWashDetailsAccess(int $lane_id): ?array
     {
         global $response;
 
@@ -1438,16 +1453,19 @@ class moduleSelfServeRoute
             return null;
         }
 
-        if (self::hasPermission($this->customerSelfServePermission())) {
+        if (self::hasPermission($this->customerSelfServeUsePermission())) {
             $customer_number = $this->resolveEffectiveCustomerNumber();
             if ($customer_number !== null && $customer_number > 0) {
-                return (int)$customer_number;
+                return [
+                    'customer_number' => (int)$customer_number,
+                    'subuser_id' => $this->authenticatedSubuserId(),
+                ];
             }
         }
 
         $this->emitForbidden([
             'modules_selfserve_lane_wash_in_progress_view',
-            $this->customerSelfServePermission(),
+            $this->customerSelfServeUsePermission(),
         ]);
         return null;
     }
@@ -1459,14 +1477,19 @@ class moduleSelfServeRoute
      * @param array<string,mixed> $payload
      * @return array<string,mixed>
      */
-    protected function scopeInProgressWashResponseForCustomer(array $payload, ?int $customer_number): array
+    protected function scopeInProgressWashResponseForCustomer(array $payload, mixed $customer_scope): array
     {
+        $scope = $this->normalizeCustomerScope($customer_scope);
+        $customer_number = $scope['customer_number'];
+        $subuser_id = $scope['subuser_id'];
+
         if ($customer_number === null || $customer_number <= 0 || ($payload['in_progress'] ?? false) !== true) {
             return $payload;
         }
 
         $session_customer_number = $this->extractInProgressWashCustomerNumber($payload);
-        if ($session_customer_number === $customer_number) {
+        $session_subuser_id = $this->extractInProgressWashSubuserId($payload);
+        if ($session_customer_number === $customer_number && ($subuser_id === null || $session_subuser_id === $subuser_id)) {
             return $payload;
         }
 
@@ -1479,6 +1502,24 @@ class moduleSelfServeRoute
         ];
     }
 
+    /**
+     * @return array{customer_number:?int,subuser_id:?int}
+     */
+    private function normalizeCustomerScope(mixed $customer_scope): array
+    {
+        if (is_array($customer_scope)) {
+            return [
+                'customer_number' => $this->normalizePositiveInt($customer_scope['customer_number'] ?? null),
+                'subuser_id' => $this->normalizePositiveInt($customer_scope['subuser_id'] ?? null),
+            ];
+        }
+
+        return [
+            'customer_number' => $this->normalizePositiveInt($customer_scope),
+            'subuser_id' => null,
+        ];
+    }
+
     /**
      * @param array<string,mixed> $payload
      */
@@ -1502,7 +1543,31 @@ class moduleSelfServeRoute
         return null;
     }
 
-    private function requireMyActiveWashCustomerNumber(): int
+    /**
+     * @param array<string,mixed> $payload
+     */
+    private function extractInProgressWashSubuserId(array $payload): ?int
+    {
+        $candidates = [
+            $payload['session']['subuser_id'] ?? null,
+            $payload['session']['subuser']['id'] ?? null,
+            $payload['subuser']['id'] ?? null,
+        ];
+
+        foreach ($candidates as $candidate) {
+            $subuser_id = $this->normalizePositiveInt($candidate);
+            if ($subuser_id !== null) {
+                return $subuser_id;
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @return array{customer_number:int,subuser_id:?int}
+     */
+    private function requireMyActiveWashPrincipalScope(): array
     {
         global $response;
 
@@ -1510,8 +1575,8 @@ class moduleSelfServeRoute
             $response->error('Authentication failed. Invalid or missing token.', 401);
         }
 
-        if (!self::hasPermission($this->customerSelfServePermission())) {
-            $this->emitForbidden([$this->customerSelfServePermission()]);
+        if (!self::hasPermission($this->customerSelfServeUsePermission())) {
+            $this->emitForbidden([$this->customerSelfServeUsePermission()]);
         }
 
         $customer_number = $this->resolveEffectiveCustomerNumber();
@@ -1519,7 +1584,10 @@ class moduleSelfServeRoute
             $response->error('No customer number found for authenticated user.', 404);
         }
 
-        return (int)$customer_number;
+        return [
+            'customer_number' => (int)$customer_number,
+            'subuser_id' => $this->authenticatedSubuserId(),
+        ];
     }
 
     private function customerSelfServePermission(): \classes\permission_node
@@ -1527,23 +1595,53 @@ class moduleSelfServeRoute
         return self::definePermission(self::CUSTOMER_SELFSERVE_PERMISSION, subusers_permission_node_key::SELFSERVE_LIST);
     }
 
+    private function customerSelfServeUsePermission(): \classes\permission_node
+    {
+        return self::definePermission(self::CUSTOMER_SELFSERVE_USE_PERMISSION, subusers_permission_node_key::SELFSERVE_ADD);
+    }
+
+    private function authenticatedSubuserId(): ?int
+    {
+        try {
+            $subuser = (new authentication())->get_subuser();
+            return $subuser === false ? null : (int)$subuser->id;
+        } catch (\Throwable) {
+            return null;
+        }
+    }
+
+    private function normalizePositiveInt(mixed $value): ?int
+    {
+        if ($value === null || $value === '') {
+            return null;
+        }
+
+        $normalized = (int)$value;
+        return $normalized > 0 ? $normalized : null;
+    }
+
     private function hasAuthenticatedUserOrSubuser(): bool
     {
         $auth = new authentication();
         return $auth->get_user() !== false || $auth->get_subuser() !== false;
     }
 
-    private function findLatestActiveSelfServeSessionForCustomer(int $customer_number): selfserve_wash_sessions_o
+    private function findLatestActiveSelfServeSessionForCustomer(int $customer_number, ?int $subuser_id = null): selfserve_wash_sessions_o
     {
         if ($customer_number <= 0) {
             return new selfserve_wash_sessions_o();
         }
 
-        $rows = (new selfserve_wash_sessions_o())->getFieldsWhere([
+        $filters = [
             'customer_number' => $customer_number,
             'completed_at' => null,
             'deleted_at' => null,
-        ], ['id', 'status']);
+        ];
+        if ($subuser_id !== null) {
+            $filters['subuser_id'] = $subuser_id;
+        }
+
+        $rows = (new selfserve_wash_sessions_o())->getFieldsWhere($filters, ['id', 'status']);
 
         $active_statuses = $this->activeSelfServeWashSessionStatusValues();
         $rows = array_values(array_filter(
@@ -1582,6 +1680,7 @@ class moduleSelfServeRoute
     {
         $lane_id = (int)$session->lane_id->value();
         $customer_number = $session->customer_number->value() === null ? null : (int)$session->customer_number->value();
+        $subuser_id = $session->subuser_id->value() === null ? null : (int)$session->subuser_id->value();
         $vehicle_id = $session->vehicle_id->value() === null ? null : (int)$session->vehicle_id->value();
         $session_reg = trim((string)$session->reg->value());
         if ($session_reg === '') {
@@ -1615,6 +1714,7 @@ class moduleSelfServeRoute
                 'lane_id' => $lane_id,
                 'reg' => $session_reg,
                 'customer_number' => $customer_number,
+                'subuser_id' => $subuser_id,
                 'vehicle_id' => $vehicle_id,
                 'vehicle_type_id' => $session->vehicle_type_id->value() === null ? null : (int)$session->vehicle_type_id->value(),
                 'included_minutes' => $included_minutes ?? 0,
@@ -1628,6 +1728,7 @@ class moduleSelfServeRoute
                 'updated_at' => $session->updated_at->value() === null ? null : (string)$session->updated_at->value(),
             ],
             'customer' => $this->buildInProgressWashCustomerPayload($customer_number),
+            'subuser' => $this->buildInProgressWashSubuserPayload($subuser_id),
             'vehicle' => $this->buildInProgressWashVehiclePayload($vehicle_id, $session_reg),
         ];
     }
@@ -1663,6 +1764,35 @@ class moduleSelfServeRoute
         ];
     }
 
+    /**
+     * @return array<string,mixed>|null
+     */
+    private function buildInProgressWashSubuserPayload(?int $subuser_id): ?array
+    {
+        if ($subuser_id === null || $subuser_id <= 0) {
+            return null;
+        }
+
+        try {
+            $subuser = (new subusers_o())->select($subuser_id);
+            if (!$subuser->exists()) {
+                return [
+                    'id' => $subuser_id,
+                ];
+            }
+
+            return [
+                'id' => (int)$subuser->id,
+                'name' => $subuser->name->value() === null ? null : (string)$subuser->name->value(),
+                'username' => $subuser->username->value() === null ? null : (string)$subuser->username->value(),
+            ];
+        } catch (\Throwable) {
+            return [
+                'id' => $subuser_id,
+            ];
+        }
+    }
+
     /**
      * @return array<string,mixed>|null
      */
@@ -2088,7 +2218,9 @@ class moduleSelfServeRoute
 
         $missing_permissions = $department_id > 0 ? ['department_access_' . $department_id] : [];
         if ($allow_customer_self_serve) {
-            $missing_permissions[] = $this->customerSelfServePermission();
+            $missing_permissions[] = $requires_active_wash
+                ? $this->customerSelfServePermission()
+                : $this->customerSelfServeUsePermission();
         }
         $this->emitForbidden($missing_permissions);
     }
@@ -2132,7 +2264,10 @@ class moduleSelfServeRoute
             return;
         }
 
-        $this->emitForbidden([...$elevated_permissions, $this->customerSelfServePermission()]);
+        $this->emitForbidden([
+            ...$elevated_permissions,
+            $requires_active_wash ? $this->customerSelfServePermission() : $this->customerSelfServeUsePermission(),
+        ]);
     }
 
     private function requireSelfServeLaneCommandPermission(
@@ -2163,7 +2298,10 @@ class moduleSelfServeRoute
 
         $this->emitForbidden(
             $allow_customer_self_serve
-                ? [...$elevated_permissions, $this->customerSelfServePermission()]
+                ? [
+                    ...$elevated_permissions,
+                    $requires_active_wash ? $this->customerSelfServePermission() : $this->customerSelfServeUsePermission(),
+                ]
                 : $elevated_permissions
         );
     }
@@ -2218,7 +2356,7 @@ class moduleSelfServeRoute
     protected function canCustomerUseSelfServeLane(selfserve_lane $lane, int $customer_number): bool
     {
         return $customer_number > 0
-            && $this->hasPermission($this->customerSelfServePermission())
+            && $this->hasPermission($this->customerSelfServeUsePermission())
             && $this->isLaneSelfServeOperationallyEnabled($lane);
     }
 
@@ -2228,8 +2366,9 @@ class moduleSelfServeRoute
             return false;
         }
 
+        $subuser_id = $this->authenticatedSubuserId();
         try {
-            if ((int)$lane->getCustomerNumber() === $customer_number) {
+            if ($subuser_id === null && (int)$lane->getCustomerNumber() === $customer_number) {
                 return true;
             }
         } catch (\Throwable) {
@@ -2238,7 +2377,7 @@ class moduleSelfServeRoute
 
         $department_id = $this->departmentIdForLane($lane);
         return $department_id > 0
-            && $this->customerHasActiveSelfServeWashInDepartment($department_id, $customer_number);
+            && $this->customerHasActiveSelfServeWashInDepartment($department_id, $customer_number, $subuser_id);
     }
 
     protected function canCustomerUsePropertyGateForLane(selfserve_lane $lane, int $customer_number): bool
@@ -2253,7 +2392,7 @@ class moduleSelfServeRoute
 
         $department_id = $this->departmentIdForLane($lane);
         return $department_id > 0
-            && $this->customerHasActiveSelfServeWashInDepartment($department_id, $customer_number);
+            && $this->customerHasActiveSelfServeWashInDepartment($department_id, $customer_number, $this->authenticatedSubuserId());
     }
 
     protected function canCustomerUseActiveOperationalSelfServeLane(
@@ -2275,8 +2414,9 @@ class moduleSelfServeRoute
             return false;
         }
 
+        $subuser_id = $this->authenticatedSubuserId();
         try {
-            if ((int)$lane->getCustomerNumber() === $customer_number) {
+            if ($subuser_id === null && (int)$lane->getCustomerNumber() === $customer_number) {
                 return true;
             }
         } catch (\Throwable) {
@@ -2294,12 +2434,17 @@ class moduleSelfServeRoute
             ]
         );
 
-        $sessions = (new selfserve_wash_sessions_o())->getFieldsWhere([
+        $filters = [
             'lane_id' => (int)$lane->id,
             'customer_number' => $customer_number,
             'completed_at' => null,
             'deleted_at' => null,
-        ], ['id', 'status']);
+        ];
+        if ($subuser_id !== null) {
+            $filters['subuser_id'] = $subuser_id;
+        }
+
+        $sessions = (new selfserve_wash_sessions_o())->getFieldsWhere($filters, ['id', 'status']);
 
         foreach ($sessions as $session) {
             if (in_array((string)($session['status'] ?? ''), $active_statuses, true)) {
@@ -2342,7 +2487,7 @@ class moduleSelfServeRoute
         }
     }
 
-    protected function customerHasActiveSelfServeWashInDepartment(int $department_id, int $customer_number): bool
+    protected function customerHasActiveSelfServeWashInDepartment(int $department_id, int $customer_number, ?int $subuser_id = null): bool
     {
         if ($department_id <= 0 || $customer_number <= 0) {
             return false;
@@ -2359,12 +2504,17 @@ class moduleSelfServeRoute
             ]
         );
 
-        $sessions = (new selfserve_wash_sessions_o())->getFieldsWhere([
+        $filters = [
             'department_id' => $department_id,
             'customer_number' => $customer_number,
             'completed_at' => null,
             'deleted_at' => null,
-        ], ['id', 'status']);
+        ];
+        if ($subuser_id !== null) {
+            $filters['subuser_id'] = $subuser_id;
+        }
+
+        $sessions = (new selfserve_wash_sessions_o())->getFieldsWhere($filters, ['id', 'status']);
 
         foreach ($sessions as $session) {
             if (in_array((string)($session['status'] ?? ''), $active_statuses, true)) {
@@ -2373,6 +2523,9 @@ class moduleSelfServeRoute
         }
 
         foreach ((new department_lanes_o())->getDepartmentLanes($department_id) as $department_lane) {
+            if ($subuser_id !== null) {
+                continue;
+            }
             try {
                 $lane = (new selfserve())->lane((int)$department_lane->id);
                 if ((int)$lane->getCustomerNumber() !== $customer_number) {
diff --git a/services/nginx/app/tests/Api/SelfserveCustomerStartApiTest.php b/services/nginx/app/tests/Api/SelfserveCustomerStartApiTest.php
index 97f989f7..692a0d21 100644
--- a/services/nginx/app/tests/Api/SelfserveCustomerStartApiTest.php
+++ b/services/nginx/app/tests/Api/SelfserveCustomerStartApiTest.php
@@ -36,6 +36,7 @@ function selfserve_customer_start_make_available(int $laneId): void
 it('allows the customer self-serve start sequence without department access', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -90,6 +91,7 @@ it('allows the customer self-serve start sequence without department access', fu
 it('marks the active customer session relay-enabled after machine relay enable', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
         'modules_selfserve_lane_relay_enable_machine',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
@@ -158,6 +160,7 @@ it('marks the active customer session relay-enabled after machine relay enable',
 it('derives allowed services from v2 session task snapshots when task rows are not legacy records', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -201,6 +204,7 @@ it('derives allowed services from v2 session task snapshots when task rows are n
 it('derives allowed services from published v2 config task snapshots when no session exists yet', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -267,6 +271,7 @@ it('derives allowed services from published v2 config task snapshots when no ses
 it('keeps questions visible but disables machine services and tasks when machine wash is globally disabled', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -316,6 +321,7 @@ it('keeps questions visible but disables machine services and tasks when machine
 it('keeps long generated task descriptions when refreshing vehicle eligibility snapshots', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -360,6 +366,7 @@ it('keeps long generated task descriptions when refreshing vehicle eligibility s
 it('does not create an active wash preview session from read-only eligibility checks', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -414,6 +421,7 @@ it('does not create an active wash preview session from read-only eligibility ch
 it('creates a durable wash session from customer start after read-only eligibility', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -482,6 +490,7 @@ it('creates a durable wash session from customer start after read-only eligibili
 it('refreshes an active wash summary with vehicle type without a namespace error', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
diff --git a/services/nginx/app/tests/Api/SelfserveLaneCommandApiTest.php b/services/nginx/app/tests/Api/SelfserveLaneCommandApiTest.php
index 65f0cfb0..7eef058a 100644
--- a/services/nginx/app/tests/Api/SelfserveLaneCommandApiTest.php
+++ b/services/nginx/app/tests/Api/SelfserveLaneCommandApiTest.php
@@ -51,6 +51,7 @@ function selfserve_lane_command_make_occupied(int $laneId, int $customerNumber,
 it('allows customer self-serve permission to execute START without department access when department and lane are enabled', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -79,6 +80,7 @@ it('allows customer self-serve permission to execute START without department ac
 it('denies customer START when department self-serve is disabled', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -98,13 +100,14 @@ it('denies customer START when department self-serve is disabled', function ():
         ->assertStatus(403)
         ->assertMissingPermissions([
             'department_access_' . (int)$scenario['department']['id'],
-            'list_own_department_selfserve_vehicle_conditions',
+            'add_own_department_selfserve_vehicle_conditions',
         ]);
 });
 
 it('denies customer START when lane self-serve is disabled', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => ['group_id' => $group['id']],
@@ -124,7 +127,7 @@ it('denies customer START when lane self-serve is disabled', function (): void {
         ->assertStatus(403)
         ->assertMissingPermissions([
             'department_access_' . (int)$scenario['department']['id'],
-            'list_own_department_selfserve_vehicle_conditions',
+            'add_own_department_selfserve_vehicle_conditions',
         ]);
 });
 
diff --git a/services/nginx/app/tests/Api/SelfserveLaneWashInProgressApiTest.php b/services/nginx/app/tests/Api/SelfserveLaneWashInProgressApiTest.php
index 3a647451..1a3a879e 100644
--- a/services/nginx/app/tests/Api/SelfserveLaneWashInProgressApiTest.php
+++ b/services/nginx/app/tests/Api/SelfserveLaneWashInProgressApiTest.php
@@ -30,7 +30,7 @@ it('reports both elevated and customer self-serve permissions when lane polling
         ->assertStatus(403)
         ->assertMissingPermissions([
             'modules_selfserve_lane_wash_in_progress_view',
-            'list_own_department_selfserve_vehicle_conditions',
+            'add_own_department_selfserve_vehicle_conditions',
         ]);
 });
 
@@ -42,13 +42,29 @@ it('requires customer self-serve permission before checking my active wash', fun
     $response
         ->assertStatus(403)
         ->assertMissingPermissions([
-            'list_own_department_selfserve_vehicle_conditions',
+            'add_own_department_selfserve_vehicle_conditions',
+        ]);
+});
+
+it('denies list-only drivers from operational self-serve active wash restore', function (): void {
+    $customer = api_fixtures()->createUser();
+    $driverSession = api_fixtures()->createSubuserSession((int)$customer['customer_number'], [
+        'SELFSERVE_LIST',
+    ]);
+
+    $response = api_client()->get('/modules/self-serve/lane/wash/my-active-wash', $driverSession['headers']);
+
+    $response
+        ->assertStatus(403)
+        ->assertMissingPermissions([
+            'add_own_department_selfserve_vehicle_conditions',
         ]);
 });
 
 it('allows customer self-serve permission to view their own in-progress wash details', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => [
@@ -74,6 +90,7 @@ it('allows customer self-serve permission to view their own in-progress wash det
 it('returns the authenticated customers active self-serve wash without requiring a lane id', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
     $scenario = api_fixtures()->createSelfServeScenario([
         'customer' => [
@@ -99,9 +116,67 @@ it('returns the authenticated customers active self-serve wash without requiring
         ->and($response->data()['vehicle']['reg'] ?? null)->toBe($scenario['vehicle']['reg']);
 });
 
+it('scopes active self-serve wash restore to the authenticated driver under a shared customer number', function (): void {
+    $scenario = api_fixtures()->createSelfServeScenario();
+    $customerNumber = (int)$scenario['customer']['customer_number'];
+    $ownerDriver = api_fixtures()->createSubuserSession($customerNumber, [
+        'SELFSERVE_LIST',
+        'SELFSERVE_ADD',
+    ], [
+        'name' => 'Self-Serve Owner Driver',
+    ]);
+    $otherDriver = api_fixtures()->createSubuserSession($customerNumber, [
+        'SELFSERVE_LIST',
+        'SELFSERVE_ADD',
+    ], [
+        'name' => 'Self-Serve Other Driver',
+    ]);
+
+    api_test_runtime()->db()->query(
+        'UPDATE selfserve_wash_sessions SET subuser_id = '
+            . (int)$ownerDriver['subuser']['id']
+            . ' WHERE id = '
+            . (int)$scenario['session']['id']
+    );
+
+    $ownerResponse = api_client()->get(
+        '/modules/self-serve/lane/wash/my-active-wash',
+        $ownerDriver['headers']
+    );
+    $otherResponse = api_client()->get(
+        '/modules/self-serve/lane/wash/my-active-wash',
+        $otherDriver['headers']
+    );
+    $otherLanePoll = api_client()->get(
+        '/modules/self-serve/lane/wash/in-progress?lane_id=' . (int)$scenario['lane']['id'],
+        $otherDriver['headers']
+    );
+
+    $ownerResponse
+        ->assertStatus(200)
+        ->assertSuccess(true);
+    $otherResponse
+        ->assertStatus(404)
+        ->assertMessage('No active self-serve wash found.');
+    $otherLanePoll
+        ->assertStatus(200)
+        ->assertSuccess(true);
+
+    expect($ownerResponse->data()['session']['subuser_id'] ?? null)->toBe((int)$ownerDriver['subuser']['id'])
+        ->and($ownerResponse->data()['subuser']['id'] ?? null)->toBe((int)$ownerDriver['subuser']['id'])
+        ->and($otherLanePoll->data())->toMatchArray([
+            'lane_id' => (int)$scenario['lane']['id'],
+            'in_progress' => true,
+            'session' => null,
+            'customer' => null,
+            'vehicle' => null,
+        ]);
+});
+
 it('returns 404 when the authenticated customer has no active self-serve wash', function (): void {
     $session = api_fixtures()->createUserSession([
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
 
     $response = api_client()->get('/modules/self-serve/lane/wash/my-active-wash', $session['headers']);
@@ -115,6 +190,7 @@ it('redacts another customers in-progress wash from customer self-serve lane pol
     $scenario = api_fixtures()->createSelfServeScenario();
     $otherSession = api_fixtures()->createUserSession([
         'list_own_department_selfserve_vehicle_conditions',
+        'add_own_department_selfserve_vehicle_conditions',
     ]);
 
     $response = api_client()->get(
diff --git a/services/nginx/app/tests/Support/Api/ApiSchemaBootstrap.php b/services/nginx/app/tests/Support/Api/ApiSchemaBootstrap.php
index 14dec108..355b088b 100644
--- a/services/nginx/app/tests/Support/Api/ApiSchemaBootstrap.php
+++ b/services/nginx/app/tests/Support/Api/ApiSchemaBootstrap.php
@@ -446,6 +446,7 @@ CREATE TABLE IF NOT EXISTS `selfserve_wash_sessions` (
     `department_id` INT NOT NULL,
     `machine_type_id` INT NULL,
     `customer_number` INT NULL,
+    `subuser_id` INT NULL,
     `vehicle_id` INT NULL,
     `vehicle_type_id` INT NULL,
     `reg` VARCHAR(255) NOT NULL,
@@ -466,6 +467,8 @@ CREATE TABLE IF NOT EXISTS `selfserve_wash_sessions` (
     KEY `idx_selfserve_wash_sessions_lane_reg` (`lane_id`, `reg`),
     KEY `idx_selfserve_wash_sessions_status` (`status`),
     KEY `idx_selfserve_wash_sessions_customer` (`customer_number`),
+    KEY `idx_selfserve_wash_sessions_subuser_active` (`subuser_id`, `completed_at`),
+    KEY `idx_selfserve_wash_sessions_customer_subuser_active` (`customer_number`, `subuser_id`, `completed_at`),
     KEY `idx_selfserve_wash_sessions_department_completed` (`department_id`, `completed_at`),
     KEY `idx_selfserve_wash_sessions_order` (`order_id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
diff --git a/services/nginx/app/tests/Unit/Selfserve/SelfserveCustomerLaneAccessTest.php b/services/nginx/app/tests/Unit/Selfserve/SelfserveCustomerLaneAccessTest.php
index 084de273..9a96ee97 100644
--- a/services/nginx/app/tests/Unit/Selfserve/SelfserveCustomerLaneAccessTest.php
+++ b/services/nginx/app/tests/Unit/Selfserve/SelfserveCustomerLaneAccessTest.php
@@ -15,6 +15,7 @@ class SelfserveCustomerLaneAccessRouteHarness extends moduleSelfServeRoute
     /** @var array<string,bool> */
     public array $permissions = [
         'list_own_department_selfserve_vehicle_conditions' => true,
+        'add_own_department_selfserve_vehicle_conditions' => true,
     ];
     public bool $laneEnabled = true;
     public bool $moduleEnabled = true;
@@ -77,11 +78,12 @@ class SelfserveCustomerLaneAccessRouteHarness extends moduleSelfServeRoute
         $method->invoke($this, $lane, $customer_number, $command_permission, $allow_customer_self_serve, $requires_active_wash);
     }
 
-    protected function customerHasActiveSelfServeWashInDepartment(int $department_id, int $customer_number): bool
+    protected function customerHasActiveSelfServeWashInDepartment(int $department_id, int $customer_number, ?int $subuser_id = null): bool
     {
         $this->activeWashChecks[] = [
             'department_id' => $department_id,
             'customer_number' => $customer_number,
+            'subuser_id' => $subuser_id,
         ];
 
         return $this->activeWashResult;
@@ -170,6 +172,7 @@ it('falls back to active department sessions for customer active wash operations
         [
             'department_id' => 4,
             'customer_number' => 12345679,
+            'subuser_id' => null,
         ],
     ]);
 });
@@ -184,6 +187,7 @@ it('blocks active wash operations for other customers', function (): void {
         [
             'department_id' => 4,
             'customer_number' => 12345679,
+            'subuser_id' => null,
         ],
     ]);
 });
diff --git a/services/nginx/app/tests/Unit/Selfserve/SelfserveInProgressWashAccessTest.php b/services/nginx/app/tests/Unit/Selfserve/SelfserveInProgressWashAccessTest.php
index 6f150e7b..b1911758 100644
--- a/services/nginx/app/tests/Unit/Selfserve/SelfserveInProgressWashAccessTest.php
+++ b/services/nginx/app/tests/Unit/Selfserve/SelfserveInProgressWashAccessTest.php
@@ -14,6 +14,14 @@ if (!class_exists(SelfserveInProgressWashAccessHarness::class)) {
         {
             return $this->scopeInProgressWashResponseForCustomer($payload, $customer_number);
         }
+
+        public function scopeForPrincipal(array $payload, int $customer_number, ?int $subuser_id): array
+        {
+            return $this->scopeInProgressWashResponseForCustomer($payload, [
+                'customer_number' => $customer_number,
+                'subuser_id' => $subuser_id,
+            ]);
+        }
     }
 }
 
@@ -74,3 +82,68 @@ it('redacts another customers in-progress wash details during customer lane poll
     ]);
 });
 
+it('keeps own driver in-progress self-serve wash details visible', function (): void {
+    $route = new SelfserveInProgressWashAccessHarness();
+
+    $payload = [
+        'lane_id' => 7,
+        'in_progress' => true,
+        'session' => [
+            'id' => 704,
+            'customer_number' => 12345679,
+            'subuser_id' => 501,
+            'reg' => 'AB12345',
+        ],
+        'subuser' => [
+            'id' => 501,
+            'name' => 'Driver One',
+        ],
+        'customer' => [
+            'customer_number' => 12345679,
+            'display_name' => 'Example Customer',
+        ],
+        'vehicle' => [
+            'id' => 55,
+            'reg' => 'AB12345',
+        ],
+    ];
+
+    expect($route->scopeForPrincipal($payload, 12345679, 501))->toBe($payload);
+});
+
+it('redacts another driver in the same customers in-progress wash during driver lane polling', function (): void {
+    $route = new SelfserveInProgressWashAccessHarness();
+
+    $scoped = $route->scopeForPrincipal([
+        'lane_id' => 9,
+        'status' => 'MACHINE_STARTED',
+        'in_progress' => true,
+        'elapsed_minutes' => 4,
+        'session' => [
+            'id' => 804,
+            'customer_number' => 12345679,
+            'subuser_id' => 502,
+            'reg' => 'CD67890',
+        ],
+        'subuser' => [
+            'id' => 502,
+            'name' => 'Driver Two',
+        ],
+        'customer' => [
+            'customer_number' => 12345679,
+            'display_name' => 'Example Customer',
+        ],
+        'vehicle' => [
+            'id' => 77,
+            'reg' => 'CD67890',
+        ],
+    ], 12345679, 501);
+
+    expect($scoped)->toBe([
+        'lane_id' => 9,
+        'in_progress' => true,
+        'session' => null,
+        'customer' => null,
+        'vehicle' => null,
+    ]);
+});
diff --git a/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php b/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
index 5bcfbd51..668b0435 100644
--- a/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
+++ b/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
@@ -336,7 +336,7 @@ it('wires self-serve property gate command permissions', function (): void {
     expect($moduleSelfServeRoute)->toContain('Failed to execute self-serve property gate command');
     expect($moduleSelfServeRoute)->toContain('$this->canCustomerUsePropertyGateForLane($lane, $customer_number)');
     expect($moduleSelfServeRoute)->toContain('$this->isOwnCustomerContext($customer_number)');
-    expect($moduleSelfServeRoute)->toContain('$this->customerHasActiveSelfServeWashInDepartment($department_id, $customer_number)');
+    expect($moduleSelfServeRoute)->toContain('$this->customerHasActiveSelfServeWashInDepartment($department_id, $customer_number, $subuser_id)');
 
     expect($commandTrait)->not->toBeFalse();
     expect($commandTrait)->toContain('Failed to open property access gate.');
@@ -351,9 +351,9 @@ it('wires in-progress self-serve wash details endpoint', function (): void {
     expect($moduleSelfServeRoute)->toContain('/modules/self-serve/lane/wash/in-progress');
     expect($moduleSelfServeRoute)->toContain('/modules/self-serve/lane/wash/my-active-wash');
     expect($moduleSelfServeRoute)->toContain('modules_selfserve_lane_wash_in_progress_view');
-    expect($moduleSelfServeRoute)->toContain('list_own_department_selfserve_vehicle_conditions');
+    expect($moduleSelfServeRoute)->toContain('add_own_department_selfserve_vehicle_conditions');
     expect($moduleSelfServeRoute)->toContain('requireInProgressWashDetailsAccess($lane_id)');
-    expect($moduleSelfServeRoute)->toContain('findLatestActiveSelfServeSessionForCustomer($customer_number)');
+    expect($moduleSelfServeRoute)->toContain('findLatestActiveSelfServeSessionForCustomer(');
     expect($moduleSelfServeRoute)->toContain('buildActiveSelfServeSessionResponse($session)');
     expect($moduleSelfServeRoute)->toContain('(new department_lanes_o())->select($lane_id)');
     expect($moduleSelfServeRoute)->toContain('self::requireDepartmentAccess((string)$department_lane->department->value())');
@@ -549,7 +549,7 @@ it('keeps read-only self-serve preview and summary refreshes from touching relay
     expect($vehicleConditionsRoute)->toContain('$summary = $flow->getLatestSessionSummary($lane_id, $reg);');
     expect($vehicleConditionsRoute)->toContain('$activate_machine = $this->requestBooleanFlag(\'activate_machine\', true);');
     expect($vehicleConditionsRoute)->toContain('$sync_relay_state = $this->requestBooleanFlag(\'sync_relay_state\', true);');
-    expect($vehicleConditionsRoute)->toContain('$this->getWashFlow()->synchronizeSession($lane, $reg, $customer_id, $activate_machine, $vehicle_type_id, $sync_relay_state);');
+    expect($vehicleConditionsRoute)->toContain('$this->getWashFlow()->synchronizeSession($lane, $reg, $customer_id, $activate_machine, $vehicle_type_id, $sync_relay_state, [');
     expect($vehicleConditionsRoute)->toContain('$this->getWashFlow()->synchronizeSession($lane_id, $reg, $customer_id, $activate_machine, $vehicle_type_id, $sync_relay_state);');
 });
 
@@ -565,7 +565,8 @@ it('classifies self-serve lane command route authorization by customer product b
     // Product flow confirms the customer UI sends STOP, while route docs expose START and property gates
     // as customer-scoped lane commands. RESERVE, RELEASE, and RESET remain absent from customer flow/docs.
     expect($productDocs)->toContain('Customer->>API: POST /modules/self-serve/lane/command (STOP)');
-    expect($productDocs)->toContain('customer `list_own_department_selfserve_vehicle_conditions` for scoped `START`, scoped `STOP`, and property gate commands');
+    expect($productDocs)->toContain('customer `add_own_department_selfserve_vehicle_conditions` for scoped `START`');
+    expect($productDocs)->toContain('customer `list_own_department_selfserve_vehicle_conditions` for scoped `STOP` and property gate commands');
     expect($productDocs)->toContain('Customer `START` requires an enabled self-serve lane. Customer `STOP` and property gate commands require the customer\'s active wash in the lane department.');
     expect($washFlow)->toContain('$payload[\'command\'] = $relayRole === \'PROPERTY_ENTRANCE\' ? \'OPEN_PROPERTY_ACCESS_GATE\' : \'OPEN_PROPERTY_EXIT_GATE\'');
     expect($washFlow)->toContain('$signalType = \'studio_action_gate_open\'');