diff --git a/API_CHANGELOG.md b/API_CHANGELOG.md
index 754d24dae..77ab8610c 100644
--- a/API_CHANGELOG.md
+++ b/API_CHANGELOG.md
@@ -16,7 +16,6 @@ Check back here regularly to stay ahead of removals.
 | Announced  | What?                                                                                                                                                                                                                      | Safe until | PR                                                            |
 |------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------|---------------------------------------------------------------|
 | 2026-04-01 | `DepartureResource.stop.*` is deprecated → use `DepartureResource.station` instead                                                                                                                                         | 2026-09-30 | [#4663](https://github.com/Traewelling/traewelling/pull/4663) |
-| 2026-04-07 | `OperatorResource.identifier` is deprecated: legacy HAFAS operator ID, always `null` for new operators                                                                                                                     | 2026-09-30 | [#4675](https://github.com/Traewelling/traewelling/pull/4675) |
 | 2026-04-07 | `OperatorResource.id` is deprecated as integer: will become a UUID after 2026-09-30. prefer `uuid` instead while migration-period                                                                                          | 2026-09-30 | [#4676](https://github.com/Traewelling/traewelling/pull/4676) |
 | 2026-05-14 | `POST /api/v1/trains/checkin` 409 response: `message.status_id` and `message.lineName` are deprecated. Use `data.conflicts` (full `StatusResource` array) instead                                                          | 2026-10-31 | [#4677](https://github.com/Traewelling/traewelling/pull/4677) |
 | 2026-07-19 | `StopoverResource.id` is deprecated as station ID: it currently holds the station ID (not unique within a trip). Use `station` for station details. After the safe-until date `id` is repurposed to the unique stopover ID | 2026-11-30 | [#4959](https://github.com/Traewelling/traewelling/pull/4959) |
@@ -27,7 +26,7 @@ Check back here regularly to stay ahead of removals.
 
 # 2026-10-17
 
-Removed the following deprecated fields, announced in 2026-03:
+Removed the following deprecated fields, announced in 2026-03 and 2026-04:
 
 - `EventDetailsResource.trainDistance`: use `totalDistance` instead
 - `EventDetailsResource.trainDuration`: use `totalDuration` instead
@@ -44,6 +43,7 @@ Removed the following deprecated fields, announced in 2026-03:
 - `StopoverResource.arrival`: use `arrivalReal` (if not null) or `arrivalPlanned` instead
 - `StopoverResource.departure`: use `departureReal` (if not null) or `departurePlanned` instead
 - `StopoverResource.rilIdentifier` and `evaIdentifier`: were always `null`, use `station.identifiers` instead
+- `OperatorResource.identifier`: legacy HAFAS operator ID, use the `identifiers` array instead
 
 Removed the following deprecated endpoints, announced in 2026-03:
 
diff --git a/app/Http/Resources/OperatorResource.php b/app/Http/Resources/OperatorResource.php
index 5bcaa3671..ff677be6c 100644
--- a/app/Http/Resources/OperatorResource.php
+++ b/app/Http/Resources/OperatorResource.php
@@ -10,7 +10,7 @@
 
 #[OA\Schema(
     schema: 'OperatorResource',
-    required: ['type', 'id', 'uuid', 'identifier', 'name', 'identifiers'],
+    required: ['type', 'id', 'uuid', 'name', 'identifiers'],
     properties: [
         new OA\Property(property: 'type', type: 'string', example: 'operator'),
         new OA\Property(
@@ -21,14 +21,6 @@
             deprecated: true
         ),
         new OA\Property(property: 'uuid', description: 'Stable UUID identifier for this operator.', type: 'string', format: 'uuid', example: '00000000-0000-0000-0000-000000000000'),
-        new OA\Property(
-            property: 'identifier',
-            description: 'Legacy HAFAS operator ID. Always NULL for new operators. Will be removed soon.',
-            type: 'string',
-            example: 'db-regio-ag-nord',
-            nullable: true,
-            deprecated: true
-        ),
         new OA\Property(property: 'name', type: 'string', example: 'DB Regio AG Nord'),
         new OA\Property(
             property: 'identifiers',
@@ -46,10 +38,6 @@ public function toArray($request): array
             'type' => 'operator', // @see https://github.com/public-transport/friendly-public-transport-format/tree/master/spec
             'id' => $this->legacy_id, // @deprecated: will become uuid after 2026-09-30
             'uuid' => $this->id, // currently NOT deprecated. But deprecate it, when ID is available -> migration uuid to id
-            'identifier' => $this->when( // @deprecated: remove after 2026-09
-                $this->relationLoaded('identifiers'),
-                fn () => $this->identifiers->firstWhere('type', 'hafas')?->identifier
-            ),
             'name' => $this->name,
             'identifiers' => $this->whenLoaded('identifiers', fn () => OperatorIdentifierResource::collection($this->identifiers)),
         ];
diff --git a/resources/types/Api.gen.ts b/resources/types/Api.gen.ts
index 403764811..1df57addd 100644
--- a/resources/types/Api.gen.ts
+++ b/resources/types/Api.gen.ts
@@ -1723,12 +1723,6 @@ export interface OperatorResource {
    * @example "00000000-0000-0000-0000-000000000000"
    */
   uuid: string;
-  /**
-   * Legacy HAFAS operator ID. Always NULL for new operators. Will be removed soon.
-   * @deprecated
-   * @example "db-regio-ag-nord"
-   */
-  identifier: string | null;
   /** @example "DB Regio AG Nord" */
   name: string;
   identifiers: OperatorIdentifierResource[];
diff --git a/storage/api-docs/api-docs.json b/storage/api-docs/api-docs.json
index 482c5f52a..bab41a411 100644
--- a/storage/api-docs/api-docs.json
+++ b/storage/api-docs/api-docs.json
@@ -14473,7 +14473,6 @@
                     "type",
                     "id",
                     "uuid",
-                    "identifier",
                     "name",
                     "identifiers"
                 ],
@@ -14494,13 +14493,6 @@
                         "format": "uuid",
                         "example": "00000000-0000-0000-0000-000000000000"
                     },
-                    "identifier": {
-                        "description": "Legacy HAFAS operator ID. Always NULL for new operators. Will be removed soon.",
-                        "type": "string",
-                        "example": "db-regio-ag-nord",
-                        "nullable": true,
-                        "deprecated": true
-                    },
                     "name": {
                         "type": "string",
                         "example": "DB Regio AG Nord"