Zip uses conventional HTTP response codes to indicate the success or failure of an API request. In general: Codes in the 2xx range indicate success. Codes in the 4xx range indicate an error that failed given the information provided (e.g., a required parameter was omitted, a charge failed, etc.). Codes in the 5xx range indicate an error with Zip's servers (these are not common).

Some 4xx errors that could be handled programmatically (e.g., a card is declined) include an error code that briefly explains the error reported.

In order to provide more information or a sub-division of status codes an Error object is returned for all non 2xx status codes. The Error object contains a more specific code and error message.

The status codes that may be returned from the API are detailed below: