Errors

The Cash-In API Service (CIAS) uses standard HTTP response codes to indicate whether a request succeeded or failed.

As a general rule:

2xx codes mean success

4xx codes mean the request was rejected due to a client-side issue.

5xx codes mean something went wrong on the Cash-In server side.

During integration, the most common errors you'll encounter are 401 and 403 — both relate to authentication. Make sure you're using the correct token for the environment you're targeting (sandbox tokens do not work in production and vice versa).

HTTP response codes

Code	Message	Description
200	OK	The request succeeded and the response body contains the result.
400	Bad request	TThe request was malformed or missing a required parameter. Check your request body and headers before retrying.
401	Unauthorized	No valid API key was provided, or the key was not included in the `X-Api-Key` header. Verify your token and that you're targeting the correct environment.
402	Request Failed	The request was well-formed but could not be completed due to a business logic constraint — for example, an invoice that is already in a terminal state.
403	Forbidden	The API key provided does not have permission to perform this action. Contact us to review the permissions assigned to your token.
404	Not Found	The requested resource does not exist, or the provided identifier does not match any record.
500	Internal Server Error	An unexpected error occurred on the Cash-In server. This should not happen in normal operation — if it persists, contact us
503	Service Unavailable	The API is temporarily unavailable, typically due to maintenance or a transient outage. Retry the request after a short delay.

Error response body

All error responses return a JSON body with the following structure:

{
  "Message": "Required parameter 'invoiceId' is missing"
}

Use the message field to understand the specific cause of the error. When contacting Cash-In support about an error, include the HTTP status code, the endpoint called, and the message value — but never include your API key in support tickets or emails.

Handling errors in your integration

4xx errors are caused by the client and will not resolve themselves by retrying the same request.

Fix the underlying issue in your request before trying again. 5xx errors may be transient. If you receive a 500 or 503, wait briefly and retry the request. If errors persist across multiple retries, contact Cash-In IT support.

Need help?

If you're unable to resolve an error, reach out via the Contact us page. When reporting an issue, include the HTTP status code, the affected endpoint, and any message value returned in the error body.

HTTP response codes#

Error response body#

Handling errors in your integration#

HTTP response codes

Error response body

Handling errors in your integration