> ## Documentation Index > Fetch the complete documentation index at: https://docs.zbx.boomfi.xyz/llms.txt > Use this file to discover all available pages before exploring further. # Register External Account > Register a payout destination the merchant controls: a wallet address (type Digital) or a bank account (type Fiat). Registering is the whitelisting step — /accounts/virtual/payout only sends to accounts created here — so this endpoint requires X-Step-Up-Token when authenticated with a Bearer session. ## OpenAPI ````yaml /openapi.yaml post /accounts/external-account openapi: 3.1.0 info: contact: email: support@boomfi.xyz name: API Support description: >- The BoomFi Merchants API provides a set of endpoints for merchants to manage their accounts, transactions, and more. Hosts differ per brand/environment; use the brand-specific base URL from the docs. title: ZBX Merchants API version: '1.0' servers: - url: https://mapi.zbx.boomfi.xyz/v1 description: Production security: [] tags: - description: Payment links name: Paylinks - description: Billing plans name: Plans - description: Subscriptions name: Subscriptions - description: Customer records name: Customers - description: Invoices name: Invoices - description: Payments name: Payments - description: Organisation events name: Events - description: Organisation profile and display settings name: Organisation - description: Webhook and request-signing secrets name: Secrets - description: Settlement accounts name: Accounts - name: Bank Address Book - description: Managed virtual accounts, balances, pay-in, and payout name: Virtual Accounts - description: Partner-managed accounts, virtual accounts, pay-in, and payout name: Partners - description: Partner virtual account automations and run history name: Partner Automations - description: Partner maintain-balance automations name: Partner Balance Monitoring - description: Tradeable currencies, instruments, and swap targets name: Instruments - description: RFQ quotes name: Quotes - description: RFQ orders and one-click trades name: Orders - description: Executed trades name: Trades paths: /accounts/external-account: post: tags: - Accounts summary: Register External Account description: >- Register a payout destination the merchant controls: a wallet address (type Digital) or a bank account (type Fiat). Registering is the whitelisting step — /accounts/virtual/payout only sends to accounts created here — so this endpoint requires X-Step-Up-Token when authenticated with a Bearer session. parameters: - description: >- Step-up token required for Bearer/session auth (ignored for API-key auth) in: header name: X-Step-Up-Token schema: type: string requestBody: content: application/json: schema: $ref: '#/components/schemas/accounts.CreateExternalAccountRequest' description: body required: true responses: '201': description: Created content: application/json: schema: $ref: >- #/components/schemas/internal.Response-accounts_ExternalAccountResponse '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/internal.ErrorResponse' '403': description: Forbidden content: application/json: schema: $ref: '#/components/schemas/internal.ErrorResponse' '409': description: Conflict content: application/json: schema: $ref: '#/components/schemas/internal.ErrorResponse' '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/internal.ErrorResponse' security: - ApiKeyAuth: [] components: schemas: accounts.CreateExternalAccountRequest: properties: account_holder_name: description: Name on the bank account. Fiat only, required. type: string account_number: description: >- Bank account number or IBAN. Fiat only, required. Encrypted at rest; only a hint is ever returned. type: string address: description: Destination wallet address. Digital only, required. type: string bank_name: description: Name of the beneficiary bank. Fiat only. type: string beneficiary_type: description: Who owns the bank account. Fiat only; defaults to business. enum: - individual - business type: string business_name: description: >- Beneficiary business name. Fiat only; defaults to account_holder_name for a business. type: string chain_id: description: Chain id. Digital only, required. example: 8453 type: integer country: description: ISO 3166-1 alpha-2 country of the bank account. Fiat only, required. example: DE type: string currencies: description: >- Currencies this account can receive. A Fiat account takes exactly one. example: - USDC items: type: string minItems: 1 type: array first_name: description: >- Beneficiary first name. Fiat only, required when beneficiary_type is individual. type: string last_name: description: >- Beneficiary last name. Fiat only, required when beneficiary_type is individual. type: string name: description: Display name. example: Treasury (Base) maxLength: 255 type: string payment_rail: description: Payment rail to settle on. Fiat only; defaults to SEPA. enum: - SEPA - SEPA_INSTANT type: string reference: description: Merchant's own reference. Payouts can name this account by it. example: treasury-base maxLength: 255 type: string type: allOf: - $ref: '#/components/schemas/docenums.CurrencyType' description: >- Kind of destination, mirroring our currency_type enum: Digital (a wallet) or Fiat (a bank account). enum: - Digital - Fiat example: Digital required: - currencies - name - reference - type type: object internal.Response-accounts_ExternalAccountResponse: properties: data: allOf: - $ref: '#/components/schemas/accounts.ExternalAccountResponse' description: Response payload when the request succeeded. error: description: True when the request failed. type: boolean message: description: Human-readable status or error message. type: string type: object internal.ErrorResponse: properties: error: allOf: - $ref: '#/components/schemas/internal.ErrorStruct' description: Error details including HTTP-style code and message. type: object docenums.CurrencyType: enum: - Fiat - Digital type: string x-enum-varnames: - CurrencyTypeFiat - CurrencyTypeDigital accounts.ExternalAccountResponse: properties: account_holder_name_hint: description: Masked account holder name. Fiat only. type: string account_number_hint: description: Masked tail of the bank account number. Fiat only. type: string address: description: Destination wallet address. Digital only. type: string bank_name: description: Name of the beneficiary bank. Fiat only. type: string beneficiary_type: description: Who owns the bank account. Fiat only. enum: - individual - business type: string chain_id: description: Chain id. Digital only. type: integer country: description: ISO 3166-1 alpha-2 country. Fiat only. type: string created_at: description: When the account was registered. type: string currencies: description: Currencies this account can receive. items: type: string type: array enabled: description: Whether this account can currently be paid out to. type: boolean id: description: >- Unique account identifier. Pass as destination_account_id when paying out. type: integer name: description: Display name. type: string payment_rail: description: Payment rail. Fiat only. enum: - SEPA - SEPA_INSTANT type: string reference: description: Merchant's own reference. type: string type: allOf: - $ref: '#/components/schemas/docenums.CurrencyType' description: Kind of destination. enum: - Digital - Fiat type: object internal.ErrorStruct: properties: code: description: |- Error code Example: 400 example: 400 type: integer errors: description: List of errors items: $ref: '#/components/schemas/internal.SingleError' type: array message: description: |- Error message Example: Insufficient quantity example: Insufficient quantity type: string type: object internal.SingleError: properties: domain: description: |- Domain Example: orders example: orders type: string reason: description: |- Error Reason Example: InsufficientQuantity example: InsufficientQuantity type: string type: object securitySchemes: ApiKeyAuth: in: header name: X-API-KEY type: apiKey ````