When working with APIs, it’s important to understand how the system responds to your requests. HTTP response codes provide clear, standardized feedback that helps developers determine whether a request was successful, needs correction, or failed due to an unexpected issue.

This section explains the most common HTTP status codes you may encounter when using Banking & Treasury APIs, along with guidance on how to interpret them.

HTTP Response Codes

Status codes indicate the outcome of your API request. They help you quickly understand whether the request was successful, requires correction, or failed due to a system-level issue. Familiarity with these codes helps developers build reliable integrations and handle API responses efficiently.

Banking & Treasury APIs use conventional HTTP response codes to indicate the success or failure of an API request and help diagnose issues during integration.

Code	Description
`2xx` range indicates success	Common codes include: `200 OK`: The request completed successfully as expected. Typically used for `GET` requests. `201 Created`: The requested resource was created successfully. The response header includes a URL that can be used to retrieve the created resource. `202 Accepted`: The request has been accepted for processing but may not be completed immediately. This response is expected for requests using Promise Mode as `ALWAYS`. `204 No Content`: The request was processed successfully but no response body is returned. Typically used for update or delete operations. `299 Warning`: The request was processed successfully, but the action may have an impact on future transactions. Additional details are provided in the warning message.
`4xx`range indicates an error that failed based on the information provided.	Common codes include: `400 Bad Request` : The request could not be processed due to malformed syntax, such as missing required parameters or incorrect formatting. `401 Unauthorized`: The access token provided is invalid or not recognized. `404 Not Found`: The requested resource does not exist. `405 Method Not Allowed`: The HTTP method used is not supported for the requested endpoint. `415 Unsupported Media Type`: The request body format is not supported by the API. `422 Unprocessable Entity`: The request was well-formed but could not be processed due to semantic errors or business validation failures. `429 Too Many Requests`: Too many requests were sent within a given timeframe. Retry after the specified period.
5xx indicates an error with PCE services	Common codes include: `5xx Server Error` – An unexpected error occurred while processing the request. These errors are rare and typically require retrying the request later or contacting support if the issue persists.

Code

Description

2xx range indicates success

Common codes include:

200 OK: The request completed successfully as expected. Typically used for GET requests.
201 Created: The requested resource was created successfully. The response header includes a URL that can be used to retrieve the created resource.
202 Accepted: The request has been accepted for processing but may not be completed immediately. This response is expected for requests using Promise Mode as ALWAYS.
204 No Content: The request was processed successfully but no response body is returned. Typically used for update or delete operations.
299 Warning: The request was processed successfully, but the action may have an impact on future transactions. Additional details are provided in the warning message.

4xxrange indicates an error that failed based on the information provided.

Common codes include:

400 Bad Request : The request could not be processed due to malformed syntax, such as missing required parameters or incorrect formatting.
401 Unauthorized: The access token provided is invalid or not recognized.
404 Not Found: The requested resource does not exist.
405 Method Not Allowed: The HTTP method used is not supported for the requested endpoint.
415 Unsupported Media Type: The request body format is not supported by the API.
422 Unprocessable Entity: The request was well-formed but could not be processed due to semantic errors or business validation failures.
429 Too Many Requests: Too many requests were sent within a given timeframe. Retry after the specified period.

5xx indicates an error with PCE services

Common codes include:

5xx Server Error – An unexpected error occurred while processing the request. These errors are rare and typically require retrying the request later or contacting support if the issue persists.

Tip: Always check the HTTP status code first. If the status code indicates an error, review the error code and message returned in the API response body for more details.