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

# Payment Requests

> Public error codes for Payment Requests API endpoints

All error responses follow the standard [error format](/api-reference/errors/error-handling).
Validation errors (422) and rate limit errors (429) apply to all endpoints and are documented in the [Error Handling guide](/api-reference/errors/error-handling).

| Code                                    | Status | Detail                                                                                                                         |
| --------------------------------------- | ------ | ------------------------------------------------------------------------------------------------------------------------------ |
| `agent_payer_not_notifiable`            | 400    | Cannot resend a payment request notification to an agent payer — agents receive in-app webhooks only.                          |
| `invalid_pagination_cursor`             | 400    | Invalid pagination cursor.                                                                                                     |
| `invalid_value`                         | 400    | The information you entered isn't valid. Please check it and try again.                                                        |
| `no_payer_contact`                      | 400    | Payment request has no contact on file to resend the notification to.                                                          |
| `unauthenticated`                       | 401    | Authentication is required.                                                                                                    |
| `forbidden`                             | 403    | You do not have permission to perform this action.                                                                             |
| `linked_account_not_found`              | 404    | Linked bank account not found.                                                                                                 |
| `payer_agent_not_found`                 | 404    | The specified payer agent does not exist.                                                                                      |
| `payer_handle_not_found`                | 404    | No account was found for the specified handle.                                                                                 |
| `payment_request_not_found`             | 404    | Payment request not found.                                                                                                     |
| `already_exists`                        | 409    | The resource already exists.                                                                                                   |
| `conflict`                              | 409    | The request conflicts with the current resource state.                                                                         |
| `wallet_closed`                         | 409    | This wallet is closed.                                                                                                         |
| `wallet_not_active`                     | 409    | You cannot request payments into a frozen wallet.                                                                              |
| `payer_agent_not_eligible`              | 422    | The specified payer agent cannot be charged for wallet-backed payments.                                                        |
| `payer_handle_invalid`                  | 422    | The specified handle is not a valid handle.                                                                                    |
| `sandbox_unknown_recipient_unsupported` | 422    | Unknown recipients are not supported in sandbox. Send payments to an existing sandbox party or create a sandbox test customer. |
| `rate_limited`                          | 429    | Too many requests. Please try again later.                                                                                     |
| `server_error`                          | 500    | Something went wrong.                                                                                                          |
| `bad_gateway`                           | 502    | We couldn't complete that request because one of Natural's services returned an unexpected response. Please try again.         |
| `service_unavailable`                   | 503    | The service is temporarily unavailable.                                                                                        |