diff --git a/services/nginx/app/routes/moduleSelfServeRoute.php b/services/nginx/app/routes/moduleSelfServeRoute.php
index ff92d84e..174395a9 100644
--- a/services/nginx/app/routes/moduleSelfServeRoute.php
+++ b/services/nginx/app/routes/moduleSelfServeRoute.php
@@ -569,6 +569,30 @@ class moduleSelfServeRoute
                     'subuser_id' => $subuser === false ? null : (int)$subuser->id,
                     ]);
                 $lane->execute($command, $args);
+                if ($command === selfserve_lane_command::START) {
+                    try {
+                        $license_plate = selfserve::standardize_registration(
+                            (string)($args->license_plate ?: $lane->getLicensePlate())
+                        );
+                        if ($license_plate !== '') {
+                            (new selfserve_wash_flow())->synchronizeSession(
+                                $lane_id,
+                                $license_plate,
+                                $customer_number > 0 ? $customer_number : null,
+                                false,
+                                null,
+                                false
+                            );
+                        }
+                    } catch (\Throwable $e) {
+                        error_log(
+                            'Failed to persist self-serve START session for lane '
+                            . $lane_id
+                            . ': '
+                            . $e->getMessage()
+                        );
+                    }
+                }
                 $response->success([
                     'id' => $lane->id,
                     'status' => $lane->getLaneStatus()->name,
diff --git a/services/nginx/app/tests/Api/SelfserveCustomerStartApiTest.php b/services/nginx/app/tests/Api/SelfserveCustomerStartApiTest.php
index 37730a61..5445d019 100644
--- a/services/nginx/app/tests/Api/SelfserveCustomerStartApiTest.php
+++ b/services/nginx/app/tests/Api/SelfserveCustomerStartApiTest.php
@@ -360,6 +360,74 @@ it('does not create an active wash preview session from read-only eligibility ch
     expect($openSession)->toBeNull();
 });
 
+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',
+    ]);
+    $scenario = api_fixtures()->createSelfServeScenario([
+        'customer' => ['group_id' => $group['id']],
+        'department_selfserve_enabled' => true,
+        'lane_selfserve_enabled' => true,
+    ]);
+    $headers = api_fixtures()->bearerHeaders(
+        api_fixtures()->createAuthToken((int)$scenario['customer']['id'])
+    );
+    $laneId = (int)$scenario['lane']['id'];
+    $reg = (string)$scenario['vehicle']['reg'];
+    $productId = (int)$scenario['product']['id'];
+    $sessionId = (int)$scenario['session']['id'];
+
+    api_test_runtime()->db()->query(
+        'DELETE FROM selfserve_wash_session_events WHERE session_id = ' . $sessionId
+    );
+    api_test_runtime()->db()->query(
+        'DELETE FROM selfserve_wash_session_tasks WHERE session_id = ' . $sessionId
+    );
+    api_test_runtime()->db()->query(
+        'DELETE FROM selfserve_wash_session_answers WHERE session_id = ' . $sessionId
+    );
+    api_test_runtime()->db()->query(
+        'DELETE FROM selfserve_wash_sessions WHERE id = ' . $sessionId
+    );
+
+    selfserve_customer_start_make_available($laneId);
+
+    api_client()
+        ->get(
+            '/department/selfserve/vehicle/allowed?lane_id=' . $laneId
+                . '&reg=' . urlencode($reg)
+                . '&vehicle_type=' . $productId,
+            $headers
+        )
+        ->assertStatus(200)
+        ->assertSuccess(true);
+
+    api_client()
+        ->post('/modules/self-serve/lane/command', [
+            'lane_id' => $laneId,
+            'command' => 'START',
+            'license_plate' => $reg,
+            'defer_relay_side_effects' => true,
+        ], $headers)
+        ->assertStatus(200)
+        ->assertSuccess(true);
+
+    $openSession = api_test_runtime()->queryOne(
+        'SELECT id, status, customer_number FROM selfserve_wash_sessions'
+            . ' WHERE lane_id = ' . $laneId
+            . ' AND reg = "' . api_test_runtime()->db()->real_escape_string($reg) . '"'
+            . ' AND completed_at IS NULL'
+            . ' AND deleted_at IS NULL'
+            . ' ORDER BY id DESC LIMIT 1'
+    );
+
+    expect($openSession)->not->toBeNull()
+        ->and((int)$openSession['customer_number'])->toBe((int)$scenario['customer']['customer_number'])
+        ->and($openSession['status'])->toBe('READY_FOR_MACHINE_START');
+
+    selfserve_customer_start_make_available($laneId);
+});
+
 it('does not create a replacement session when refreshing a completed summary with vehicle type', function (): void {
     $group = api_fixtures()->createGroup([], [
         'list_own_department_selfserve_vehicle_conditions',
diff --git a/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php b/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
index bbb2f6fc..87ba8a63 100644
--- a/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
+++ b/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
@@ -509,6 +509,10 @@ it('classifies self-serve lane command route authorization by customer product b
     expect($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('$signalType = \'studio_action_gate_open\'');
+    expect($moduleSelfServeRoute)
+        ->toContain('if ($command === selfserve_lane_command::START)')
+        ->toContain('(new selfserve_wash_flow())->synchronizeSession(')
+        ->toContain('Failed to persist self-serve START session');
 
     $commandCases = selfserve_lane_command_route_cases($moduleSelfServeRoute);