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

# Calculate Single Transfer Fee

> Calculate the fee for a single transfer before initiating it. Use this to show your users the exact cost.

Calculate the fee for a single transfer before initiating it. Use this to show your users the exact cost.

## Endpoint

```
POST /api/v1/business/fee/single
```

**Signature required:** Yes

## Headers

| Header                       | Required | Description                                                                                                                                                                    |
| ---------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `X-Numero-Api-Key`           | Yes      | Your API key                                                                                                                                                                   |
| `X-Numero-Signature`         | Yes      | Base64 HMAC-SHA256 over the exact raw request body (POST) or the canonicalised query string (GET), keyed with your **Public Key**. See [Request signing](/03-request-signing). |
| `X-Numero-Signature-Version` | Yes      | Always `v2`.                                                                                                                                                                   |

## Request body

| Field    | Type   | Required | Description                  |
| -------- | ------ | -------- | ---------------------------- |
| `amount` | number | Yes      | The transfer amount in Naira |

## Request example

```bash theme={null}
curl -X POST "https://api.usenumero.com/numeroaccount/api/v1/business/fee/single" \
  -H "Content-Type: application/json" \
  -H "X-Numero-Api-Key: your_api_key" \
  -H "X-Numero-Signature: $SIGNATURE" \
  -H "X-Numero-Signature-Version: v2" \
  -d '{
    "amount": 50000
  }'
```

## Response

```json theme={null}
{
  "data": {
    "totalAmount": 50000.0,
    "numeroFee": 15.0,
    "stampDuty": 50.0,
    "totalFee": 65.0,
    "totalDeductible": 50065.0
  },
  "error": null,
  "meta": {
    "request_id": "req_365123ebc73323f1482508560ce6400e",
    "pagination": null
  }
}
```

| Field             | Type   | Description                                                                                       |
| ----------------- | ------ | ------------------------------------------------------------------------------------------------- |
| `totalAmount`     | number | The original transfer amount                                                                      |
| `numeroFee`       | number | The fee you're charged for this transfer                                                          |
| `stampDuty`       | number | NGN stamp duty (₦50 on third-party NGN transfers ≥ ₦10,000) — a government levy, not a Numero fee |
| `totalFee`        | number | Total fee (`numeroFee` + `stampDuty`)                                                             |
| `totalDeductible` | number | Total amount that will be deducted from your balance                                              |