# Assign a number to a customer

Source: https://joinsimplesms.com/docs/api/numbers/update
Index: https://joinsimplesms.com/llms.txt

`PATCH /v1/numbers/{id}`

Send your API key as a bearer token: `Authorization: Bearer ssms_sk_...`. Test keys run this endpoint against the [sandbox](/docs/sandbox); see [Authentication](/docs/authentication) for key modes and scopes.

## Path parameters

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `id` | string | Yes | The E.164 number |

## Request body

JSON (`Content-Type: application/json`).

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `customer_id` | string | Yes | A customer id, or null to unassign Nullable. |

## Responses

| Status | Meaning | Body |
| --- | --- | --- |
| 200 | The updated number | `Number` |
| 400 | Unknown customer | `Error` |
| 401 | Missing, malformed, or revoked API key | `Error` |
| 402 | Billable live calls only: the prepaid credit balance cannot cover the call (insufficient_credits); nothing was done or charged | `Error` |
| 404 | Not found | `Error` |
| 429 | Rate limit or quota exceeded | `Error` |

### 200: `Number` fields

| Field | Type | Description |
| --- | --- | --- |
| `id` | string | Example: `+15005550132`. |
| `object` | `number` |  |
| `phone_number` | string |  |
| `status` | `active`, `released` |  |
| `mode` | `test`, `live` |  |
| `created_at` | string (date-time) |  |
| `customer_id` | string | The customer this number is assigned to Nullable. |
| `label` | string | Nullable. |
| `tags` | array of string |  |
| `pools` | array of string | Pool ids |
| `sender` | object | How the number stands with the carriers. null on sandbox numbers and on numbers that need no registration (toll-free, Canadian). Only an active number can text anyone; in every other state it can text only your verified numbers. Nullable. |
| `sender.state` | `test_only`, `pending`, `active`, `action_needed` | test_only: no registration submitted. pending: a registration is in review, or approved and being linked. active: linked to an approved registration. action_needed: see reason. |
| `sender.registration_id` | string | The registration it is (being) linked to Nullable. |
| `sender.reason` | string | What to do, in plain words, when state is action_needed Nullable. |
| `sender.updated_at` | string (date-time) |  |

## Errors

| Status | When |
| --- | --- |
| 400 | Unknown customer |
| 401 | Missing, malformed, or revoked API key |
| 402 | Billable live calls only: the prepaid credit balance cannot cover the call (insufficient_credits); nothing was done or charged |
| 404 | Not found |
| 429 | Rate limit or quota exceeded |

Every error has the same JSON shape, and `request_id` matches the `X-Request-Id` response header. [Errors](/docs/errors) lists every code and what to do about it.

```json
{
  "error": {
    "code": "invalid_request",
    "message": "What went wrong, in plain words.",
    "param": "the_field",
    "request_id": "req_a1B2c3D4e5F6g7H8"
  }
}
```

## Examples

### curl

```bash
curl -X PATCH "https://api.joinsimplesms.com/v1/numbers/+15005550132" \
  -H "Authorization: Bearer $SIMPLESMS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "customer_id": "string"
}'
```

### Node.js

```javascript
import { SimpleSMS } from 'joinsimplesms'; // npm install joinsimplesms

const sms = new SimpleSMS(process.env.SIMPLESMS_API_KEY);

const number = await sms.numbers.update('+14155550132', { customerId: 'cus_a1B2c3D4e5F6g7' });
```

### Python

```python
import os
from joinsimplesms import SimpleSMS  # pip install joinsimplesms

client = SimpleSMS(os.environ["SIMPLESMS_API_KEY"])

number = client.numbers.update("+14155550132", customer_id="cus_a1B2c3D4e5F6g7")
```

## Related

- Guide: [Numbers](/docs/numbers)
- [All numbers endpoints](/docs/api#numbers)
- [API reference](/docs/api)