> ## 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.

> ## Agent Instructions
> When building application code, use `@naturalpay/sdk` for TypeScript or `naturalpay` for Python.
> When operating Natural directly for a user, use the payments MCP at `https://mcp.natural.com`.
> When searching Natural documentation, use the docs MCP at `https://docs.natural.com/mcp`.
> Use the Natural CLI for terminal and CI automation.
> Use REST only for unsupported languages or when the user explicitly requests raw HTTP.
> Start integration development and testing in the sandbox. Do not use production unless the user explicitly requests it.
> For sandbox requests that require `customerPartyId`, list customers first. Reuse only the intended fixture; otherwise create a customer.
> REST and SDK amounts use integer minor units. Payments MCP amounts use decimal strings with a required currency code.

# External Party Accounts

> Public error codes for External Party Accounts 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                                                                                                                 |
| ---------------------------------------------------------- | ------ | ---------------------------------------------------------------------------------------------------------------------- |
| `external_party_account.invalid_encrypted_account_details` | 400    | Encrypted bank account details are invalid.                                                                            |
| `external_party_account.rejected`                          | 400    | Bank account could not be created.                                                                                     |
| `external_party_account.validation_failed`                 | 400    | Bank account validation failed.                                                                                        |
| `external_party_account.validation_input_invalid`          | 400    | Bank account details were rejected by validation.                                                                      |
| `external_party.archived`                                  | 400    | External party is archived.                                                                                            |
| `external_party.individual_name_incomplete`                | 400    | Individual external party names must include first and last name.                                                      |
| `external_party.screening_not_clear`                       | 400    | External party screening is not clear.                                                                                 |
| `invalid_value`                                            | 400    | The information you entered isn't valid. Please check it and try again.                                                |
| `unauthenticated`                                          | 401    | Authentication is required.                                                                                            |
| `direct.not_enabled`                                       | 403    | Direct is not enabled for this program.                                                                                |
| `forbidden`                                                | 403    | You do not have permission to perform this action.                                                                     |
| `not_found`                                                | 404    | The requested resource was not found.                                                                                  |
| `already_exists`                                           | 409    | The resource already exists.                                                                                           |
| `conflict`                                                 | 409    | The request conflicts with the current resource state.                                                                 |
| `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. |
| `external_party_account.account_details_unavailable`       | 503    | Bank account details are temporarily unavailable.                                                                      |
| `external_party_account.account_fingerprint_unavailable`   | 503    | Bank account fingerprinting is temporarily unavailable.                                                                |
| `external_party_account.account_tokenization_unavailable`  | 503    | Bank account tokenization is temporarily unavailable.                                                                  |
| `service_unavailable`                                      | 503    | The service is temporarily unavailable.                                                                                |