> ## Documentation Index > Fetch the complete documentation index at: https://docs.cadanapay.com/llms.txt > Use this file to discover all available pages before exploring further. # Submit Tax Form > Submit a completed W9, W8BEN or W8BENE tax form. Provide a fileId for the signed document (from the files API) and the raw field data. ## OpenAPI ````yaml /openapi/workforce-management.yaml post /v1/users/{userId}/tax-forms openapi: 3.0.0 info: description: APIs for interacting with Cadana Payroll Platform version: 1.0.0 title: Business Workforce Management termsOfService: https://cadanapay.com/terms-and-conditions contact: email: api@cadanapay.com license: name: Apache 2.0 url: http://www.apache.org/licenses/LICENSE-2.0.html servers: - url: https://api.cadanapay.com description: Prod Server - url: https://dev-api.cadanapay.com description: Dev Server security: - Authorization: [] tags: - name: Custom Auth description: APIs for interacting with Custom Authentication - name: Persons description: APIs for interacting with the HR module - name: Milestones description: APIs for milestone-based contractor pay - name: Instant Pay description: APIs for interacting with Instant Pay functionality - name: Users description: APIs for interacting with employee/contractor Cadana accounts - name: Files description: APIs for interacting with file uploads - name: Payrolls description: APIs for interacting with Payroll - name: Platform description: Platform APIs for interacting with businesses - name: Businesses description: APIs for interacting with Business - name: Treasury description: APIs for business balances, funding, and withdrawals - name: KYB description: APIs for business verification - name: Contracts description: APIs for interacting with contracts - name: Sandbox description: APIs for relevant sandbox simulations - name: Invoices description: APIs for interacting with invoices - name: Reimbursements description: APIs for interacting with reimbursements - name: Entities description: >- APIs for managing legal sub-entities (subsidiaries, branches) under a parent business paths: /v1/users/{userId}/tax-forms: post: tags: - Users summary: Submit Tax Form description: >- Submit a completed W9, W8BEN or W8BENE tax form. Provide a fileId for the signed document (from the files API) and the raw field data. operationId: submitUserTaxForm parameters: - $ref: '#/components/parameters/userId' - $ref: '#/components/parameters/XMultiTenantKey' requestBody: content: application/json: schema: $ref: '#/components/schemas/UploadTaxFormRequest' responses: '200': description: upload tax form response content: application/json: schema: type: object properties: id: $ref: '#/components/schemas/uuid' example: id: ca51f42c-0adc-4a77-8dd1-a03dd4fb955f '400': $ref: '#/components/responses/BadRequestError' 5XX: $ref: '#/components/responses/InternalError' security: - Authorization: [] components: parameters: userId: name: userId in: path description: The unique identifier for the user required: true schema: type: string format: uuid XMultiTenantKey: name: X-MultiTenantKey in: header required: false schema: type: string description: >- Required when using a Platform API token. The tenant key identifying which business to operate on. schemas: UploadTaxFormRequest: type: object required: - fileId - type description: >- Provide `fileId`, `type`, and exactly one form object (`w9`, `w8ben` or `w8bene`) matching `type`. example: fileId: 517075a2-17db-469f-9481-eb8347cb920c type: W9 w9: firstName: John lastName: Doe email: john.doe@email.com entityType: Individual taxIdType: SSN taxIdNumber: '123456789' address: line1: House 1 city: New York City state: NY postalCode: '10001' countryCode: US properties: fileId: $ref: '#/components/schemas/uuid' type: type: string description: Tax form type enum: - W9 - W8BEN - W8BENE example: W9 w9: $ref: '#/components/schemas/W9FormData' w8ben: $ref: '#/components/schemas/W8BENFormData' w8bene: $ref: '#/components/schemas/W8BENEFormData' uuid: type: string format: uuid example: 8ef9a712-cdae-4110-b1ea-9ba95abbee6e W9FormData: type: object required: - firstName - lastName - entityType - taxIdType - taxIdNumber properties: firstName: type: string example: John lastName: type: string example: Doe email: type: string format: email example: john.doe@email.com businessName: type: string example: Doe LLC entityType: type: string description: Individual, Corporation, S Corporation, Partnership, Trust or LLC example: Individual address: $ref: '#/components/schemas/address' taxIdType: type: string description: SSN or EIN example: SSN taxIdNumber: type: string description: 9 digit tax identification number example: '123456789' W8BENFormData: type: object required: - firstName - lastName - taxIdNumber properties: firstName: type: string example: John lastName: type: string example: Doe email: type: string format: email example: john.doe@email.com address: $ref: '#/components/schemas/address' mailingAddress: $ref: '#/components/schemas/address' dob: type: string description: Date of birth (YYYY-MM-DD) example: '1990-01-15' taxIdType: type: string description: SSN, ITIN or Other example: SSN taxIdNumber: type: string example: '123456789' W8BENEFormData: type: object required: - firstName - lastName - businessName - taxIdNumber properties: firstName: type: string example: John lastName: type: string example: Doe email: type: string format: email example: john.doe@email.com businessName: type: string example: Doe Global Inc companyType: type: string description: Corporation or Partnership example: Corporation address: $ref: '#/components/schemas/address' mailingAddress: $ref: '#/components/schemas/address' taxIdType: type: string description: TIN, GIIN or Other example: TIN taxIdNumber: type: string example: '123456789' BadRequestError: description: Bad input provided by client allOf: - $ref: '#/components/schemas/Error' - type: object properties: params: description: A map for meta data around the error that occurred type: object example: code: invalid_request_body message: The request body provided is not valid params: field: Value is invalid. InternalError: description: Internal server error allOf: - $ref: '#/components/schemas/Error' example: code: internal_error message: An unexpected error occurred. Please try again later. address: type: object description: Address required: - countryCode properties: line1: type: string example: Street 1 line2: type: string example: Apt 1 city: type: string example: Gotham postalCode: type: string example: '10001' state: type: string example: NY countryCode: type: string example: US Error: type: object properties: code: description: A machine parsable error code type: string enum: - invalid_request_body - resource_not_found - forbidden - internal_error message: description: A human readable message describing the error type: string responses: BadRequestError: description: Bad input provided by client content: application/json: schema: $ref: '#/components/schemas/BadRequestError' InternalError: description: Internal error content: application/json: schema: $ref: '#/components/schemas/InternalError' securitySchemes: Authorization: type: http scheme: bearer bearerFormat: API_SECRET_KEY ````