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

# Transfers & Payments

> Intra-bank transfers, NIP inter-bank payments, CBN fee caps, and idempotency guarantees.

Nucleus provides real-time fund transfer processing across intra-bank accounts and external payment rails (NIP, Remita, Interswitch).

## Idempotency Invariant

<Note>
  All transfer requests should include an `Idempotency-Key` header. If a network timeout occurs, re-sending with the same key returns the original transaction state without executing a duplicate debit.
</Note>

***

## 1. Intra-Bank Account Transfer

```bash theme={null}
POST /nucleus/api/v1/accounttransfers?tenantIdentifier=pilot-mfb
Idempotency-Key: idemp_9f81a7b6-c5d4-4e21
Content-Type: application/json

{
  "fromOfficeId": 2,
  "fromClientId": 1,
  "fromAccountType": 2,
  "fromAccountId": 12,
  "toOfficeId": 2,
  "toClientId": 3,
  "toAccountType": 2,
  "toAccountId": 18,
  "transferAmount": 75000.00,
  "transferDate": "12 September 2026",
  "transferDescription": "Consulting fee payment",
  "dateFormat": "dd MMMM yyyy",
  "locale": "en"
}
```

***

## 2. NIP Inter-Bank Transfer (Outbound)

Outbound transfers to other commercial and microfinance banks in Nigeria:

```bash theme={null}
POST /nucleus/api/v1/interop/transactions?tenantIdentifier=pilot-mfb
Content-Type: application/json

{
  "fromAccountId": 12,
  "destinationBankCode": "000014",
  "destinationAccountNo": "0123456789",
  "beneficiaryName": "Babajide Sanwo-Olu",
  "amount": 250000.00,
  "currency": "NGN",
  "narration": "Project milestone delivery",
  "cbnFee": 50.00,
  "vat": 3.75
}
```

### Response:

```json theme={null}
{
  "transactionId": "TXN-20260912-9901",
  "sessionKey": "00001426091211000091238471928471",
  "status": "SUCCESSFUL",
  "amount": 250000.00,
  "fee": 53.75,
  "settledAt": "2026-09-12T11:05:22Z"
}
```