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

# Managing Account Numbers

> Create, assign, and manage the lifecycle of Account Numbers.

| **Endpoint**                                             | **Description**                                                                                             |
| :------------------------------------------------------- | :---------------------------------------------------------------------------------------------------------- |
| `POST /v1/account_number`                                | Create an Account Number, optionally assigning it a `client_customer_id` or `entity_id` at creation.        |
| `POST /v1/account_number/{account_number_id}/assign`     | Assign an unassigned Account Number to a customer. Pass exactly one of `client_customer_id` or `entity_id`. |
| `PATCH /v1/account_number/{account_number_id}`           | Update controls or metadata.                                                                                |
| `POST /v1/account_number/{account_number_id}/activate`   | Reactivate an `inactive` Account Number.                                                                    |
| `POST /v1/account_number/{account_number_id}/deactivate` | Deactivate an `active` Account Number. It can no longer send or receive.                                    |
| `POST /v1/account_number/{account_number_id}/cancel`     | Permanently cancel an Account Number. Terminal; the number is not recycled.                                 |

An Account Number can send and receive transfers only while it is `active`; see [Statuses](/products/account-number/statuses) for the full lifecycle and [Payment Controls](/products/account-number/controls) for the per-rail settings you can manage with the update endpoint.