> ## Documentation Index
> Fetch the complete documentation index at: https://baas-api-docs.rexmfbank.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Transfer between Rex-issued accounts

> Moves money between any two Rex-issued accounts — including across
partners. If the beneficiary belongs to a different partner, that
partner's webhook fires an `internal-transfer` event too.
`reference` must be unique per transaction — reusing one returns
`409 DUPLICATE_REFERENCE`, safe to retry with the same reference on
a network timeout.




## OpenAPI

````yaml /openapi.yaml post /services/virtual-account/internal-transfer
openapi: 3.1.0
info:
  title: Rex Banking-as-a-Service API
  version: 1.0.0
  summary: Embed real bank accounts, transfers, and collections into your product.
  description: |
    The Rex BaaS API lets you provision virtual bank accounts, move money
    between them, accept inbound transfers, and collect at merchant terminals —
    all under your own brand, backed by a real bank ledger.

    This reference covers every endpoint your integration will call. If
    you're just getting started, read **[Getting Started](/introduction)**
    and **[Authentication](/authentication)** first — most integration
    questions are answered there, not in the endpoint list.

    All endpoints are versioned under `/baas/api/v1` and return JSON. See
    **[Errors](/errors)** for the shared error envelope, and
    **[Sandbox vs. Live](/guides/sandbox-vs-live)** for how test and
    production credentials differ.
  contact:
    name: Rex BaaS Support
    email: baas-support@rexmfbank.com
  license:
    name: Proprietary — for approved Rex BaaS partners only
servers:
  - url: https://api.rexmfbank.com/baas/api/v1
    description: Live
  - url: https://sandbox-api.rexmfbank.com/baas/api/v1
    description: Sandbox
security:
  - BearerAuth: []
tags:
  - name: Authentication
    description: Register a partner account, verify it, log in, and manage credentials.
  - name: Onboarding
    description: |
      The one-time KYB (Know Your Business) flow every partner completes
      before going live — business details, a compliance representative,
      supporting documents, and signing the partner agreement.
  - name: Wallet
    description: >-
      Your business's own settlement balance — the account every virtual account
      nets into.
  - name: Virtual Accounts
    description: |
      The core product — dedicated bank account numbers you issue to your
      own end users, with full transfer and transaction capabilities.
  - name: Webhooks
    description: Configure where and how Rex notifies your system of events in real time.
  - name: Partner Settings
    description: >-
      Account security, team members, disputes, and document management for your
      own partner account.
paths:
  /services/virtual-account/internal-transfer:
    post:
      tags:
        - Virtual Accounts
      summary: Transfer between Rex-issued accounts
      description: |
        Moves money between any two Rex-issued accounts — including across
        partners. If the beneficiary belongs to a different partner, that
        partner's webhook fires an `internal-transfer` event too.
        `reference` must be unique per transaction — reusing one returns
        `409 DUPLICATE_REFERENCE`, safe to retry with the same reference on
        a network timeout.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - sourceAccountNo
                - beneficiaryAccountNo
                - amount
                - narration
                - reference
              properties:
                sourceAccountNo:
                  type: string
                beneficiaryAccountNo:
                  type: string
                amount:
                  type: number
                  format: float
                  minimum: 0.01
                narration:
                  type: string
                  maxLength: 100
                reference:
                  type: string
                  maxLength: 191
                  description: Your own idempotency key for this transfer.
                geolocation:
                  type: string
                  nullable: true
                charge:
                  type: number
                  nullable: true
                stampDuty:
                  type: number
                  nullable: true
                channel:
                  type: string
                  nullable: true
      responses:
        '200':
          description: OK
          content:
            application/json:
              example:
                status: success
                message: Internal transfer SUCCESSFUL.
                data:
                  reference: REF-001
                  transactionStatus: SUCCESSFUL
        '400':
          description: '`INSUFFICIENT_BALANCE` or `REGULAR_ACCOUNT_NOT_SUPPORTED_IN_SANDBOX`'
        '404':
          description: '`SOURCE_ACCOUNT_NOT_FOUND` or `BENEFICIARY_ACCOUNT_NOT_FOUND`'
        '409':
          description: >-
            `DUPLICATE_REFERENCE`, `FBO_NOT_PROVISIONED`, or
            `DESTINATION_FBO_NOT_PROVISIONED`
        '422':
          description: '`INVALID_TRANSFER` — source and beneficiary are the same account'
components:
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      bearerFormat: sk_live_... / sk_sandbox_...
      description: |
        See **[Authentication](/authentication)** for the full explanation
        of session tokens vs. API keys and when each is used.

````