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

# SPEI codes

When an inbound or outbound transfer through Mexico's Interbank Electronic Payment System (SPEI) is
returned, the `return_reason` describes why. The following table lists the return reasons, codes, and
available guidance.

| Code | Reason                                                     | Description                                                                                                                           |
| :--- | :--------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------ |
| `01` | `non_existent_account`                                     | The destination account number does not exist. Verify that the number is correct.                                                     |
| `02` | `blocked_account`                                          | The destination account is blocked. Ask the account holder for details or a different account.                                        |
| `03` | `canceled_account`                                         | The destination account is closed. Ask the account holder for details or a different account.                                         |
| `05` | `account_in_different_currency`                            | The destination account is in a different currency than your originating account. Use an account in the same currency.                |
| `06` | `account_does_not_belong_to_receiving_participant`         | The destination account and institution do not match. Confirm that you are using the correct institution.                             |
| `16` | `wrong_operation_type`                                     | The operation code or type is invalid.                                                                                                |
| `17` | `account_type_does_not_correspond`                         | The destination account does not receive SPEI transfers. Use a different account.                                                     |
| `20` | `exceeds_authorized_account_balance_limit`                 | The recipient account has reached its holding limit. Retry when the account is below the limit.                                       |
| `21` | `exceeds_allowed_deposit_limit_for_the_month`              | The recipient account has reached its monthly limit. Retry after the monthly limit resets.                                            |
| `22` | `mobile_phone_line_number_not_registered`                  | The recipient's mobile phone number is not registered. Verify the number with the account holder.                                     |
| `25` | `account_with_restriction_for_spei_payments`               | The destination account does not receive SPEI transfers. Use a different account.                                                     |
| `26` | `recipient_participant_has_decided_not_to_accept_payments` | The receiving bank does not accept payments from specific issuing participants or under specific conditions. Use a different account. |
| `27` | `optional_payment_not_accepted_by_receiving_participant`   | The receiving bank does not support the additional payment type.                                                                      |