> ## 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.

# Get Cardholder

> Retrieve a single cardholder by id.

Returns a single cardholder by their `customerId`.

> Card endpoints use the same base URL and API key as the rest of the API, and are signature-gated:
> send `X-Numero-Signature` and `X-Numero-Signature-Version: v2` as well. See [Request signing](/03-request-signing).

## Endpoint

```
GET /api/v1/business/cardholders/{customerId}
```

**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`.                                                                                                                                                                   |

## Path parameters

| Parameter    | Type   | Required | Description       |
| ------------ | ------ | -------- | ----------------- |
| `customerId` | string | Yes      | The cardholder id |

## Request example

```bash theme={null}
curl -X GET "https://api.usenumero.com/numeroaccount/api/v1/business/cardholders/NCUS9953596C2B7F45" \
  -H "X-Numero-Api-Key: your_api_key" \
  -H "X-Numero-Signature: $SIGNATURE" \
  -H "X-Numero-Signature-Version: v2"
```

## Response

```json theme={null}
{
  "data": {
    "customerId": "NCUS9953596C2B7F45",
    "firstName": "Ada",
    "lastName": "Obi",
    "email": "ada@example.com",
    "phone": "08012345678",
    "country": "NG",
    "status": "Active",
    "activeCardCount": 1,
    "createdAt": "2026-06-16T12:00:00Z"
  },
  "error": null,
  "meta": {
    "request_id": "req_365123ebc73323f1482508560ce6400e",
    "pagination": null
  }
}
```