> ## Documentation Index > Fetch the complete documentation index at: https://docs.filexpress.app/llms.txt > Use this file to discover all available pages before exploring further. # Assign cost center to a payroll > The payroll's center (`null` removes it; omitted leaves it unchanged) and, per employee, its own center (`null` = uses the payroll's). When posting, salary and employer contribution expenses are grouped by account and center. Instead of a center, `cost_center_distribution_id` can be sent (payroll or employee): the expense is split by percentage. It does not modify journal entries already generated. **Required permission:** `hr.payrolls.write` ## OpenAPI ````yaml /api-reference/openapi.en.json put /hr/payrolls/{id}/cost-center openapi: 3.0.3 info: title: FileXpress External API version: 1.0.0 description: >- API for integrating third-party systems with FileXpress: billing, HR, accounting, inventory, projects, accounts receivable and payable, treasury, pricing and promotions, and cash. Current base URL: /api/external/v1. The legacy unversioned path (/api/external) will be removed on January 1, 2027; migrate to /api/external/v1 (same endpoints, only the base URL changes). The v2 API (/api/external/v2) exposes currencies and exchange rates, sales and purchases in foreign currency, taxes by id, payrolls with branch, and errors with a stable `code`; its operations carry the /v2 prefix in the path. We suggest migrating to the available v2 routes before March 30, 2027. servers: - url: https://api.filexpress.app/api/external/v1 description: Production security: - ApiKey: [] tags: - name: General - name: Billing · Sales - name: Billing · Purchases - name: Billing · Customers - name: Billing · Suppliers - name: Billing · Products - name: Catalogs - name: HR · Employees - name: HR · Attendance - name: HR · Labor rules - name: HR · Schedules - name: HR · Holidays - name: HR · Attendance results - name: HR · Leave requests - name: HR · Payrolls - name: Accounting - name: Inventory - name: Projects - name: Accounts receivable - name: Accounts payable - name: Treasury - name: Pricing and promotions - name: Cash - name: Points of sale - name: API v2 · General - name: API v2 · Currencies and rates - name: API v2 · Countries - name: API v2 · Sales - name: API v2 · Purchases - name: API v2 · Payrolls paths: /hr/payrolls/{id}/cost-center: put: tags: - HR · Payrolls summary: Assign cost center to a payroll description: >- The payroll's center (`null` removes it; omitted leaves it unchanged) and, per employee, its own center (`null` = uses the payroll's). When posting, salary and employer contribution expenses are grouped by account and center. Instead of a center, `cost_center_distribution_id` can be sent (payroll or employee): the expense is split by percentage. It does not modify journal entries already generated. **Required permission:** `hr.payrolls.write` parameters: - name: id in: path required: true description: Payroll ID schema: type: string format: uuid example: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/PayrollCostCenterRequest' example: cost_center_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 details: - employee_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 cost_center_id: null responses: '200': description: Success content: application/json: schema: type: object required: - status - data properties: status: type: boolean example: true data: type: object properties: id: type: string format: uuid cost_center_id: type: string format: uuid nullable: true details: type: array items: type: object properties: employee_id: type: string format: uuid cost_center_id: type: string format: uuid nullable: true required: - employee_id required: - id - cost_center_id - details example: status: true data: id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 cost_center_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 cost_center_distribution_id: null details: - employee_id: 3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01 cost_center_id: null cost_center_distribution_id: 9d1c5a3e-4b7f-4e2a-9c1d-2f6b8a0e7c11 '401': $ref: '#/components/responses/E401' '403': $ref: '#/components/responses/E403' '404': description: Not found or belongs to another business content: application/json: schema: $ref: '#/components/schemas/Error' example: status: false message: Payroll not found '422': description: Validation, employee not in the payroll, or invalid center content: application/json: schema: $ref: '#/components/schemas/Error' example: status: false message: Validation errors errors: details.0.employee_id: El empleado no pertenece a esta planilla. '429': $ref: '#/components/responses/E429' components: schemas: PayrollCostCenterRequest: type: object properties: cost_center_id: type: string format: uuid nullable: true description: >- Cost center of the payroll; null removes it, omitted leaves it unchanged. details: type: array maxItems: 2000 items: type: object properties: employee_id: type: string format: uuid description: Employee of the payroll. cost_center_id: type: string format: uuid nullable: true description: null = uses the payroll's. cost_center_distribution_id: type: string format: uuid nullable: true description: >- Distribution of the employee. Mutually exclusive with `cost_center_id` at the same level (422 `Indique centro de costo o distribución, no ambos.`). required: - employee_id cost_center_distribution_id: type: string format: uuid nullable: true description: >- Distribution of the payroll; null removes it, omitted leaves it unchanged. Mutually exclusive with `cost_center_id` at the same level (422 `Indique centro de costo o distribución, no ambos.`). Error: type: object properties: status: type: boolean example: false message: type: string errors: type: object additionalProperties: type: array items: type: string description: Errors per field (validation only). required: - status - message responses: E401: description: Missing or invalid API Key content: application/json: example: status: false message: Invalid API Key. E403: description: Integration without the required permission or deactivated content: application/json: example: status: false message: This integration does not have the 'hr.employees' permission. required_scope: hr.employees E429: description: Rate limit exceeded content: application/json: example: status: false message: Rate limit exceeded. Please try again later. rate_limit: 100 securitySchemes: ApiKey: type: apiKey in: header name: X-API-Key description: Integration API Key (Integrations → New Integration). ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.