API status codes

2xx = OK

All status codes starting with a 2 (e.g. 201) represent success.

Please note: in some systems such as Klaviyo, anything other that 200 (for example 201) is still shown as an error message in red. So this might look like an error, but it is not.


All codes that start with a 4 indicate a problem on the user side, check for example if you have all template IDs in your JSON correctly. An error in the design could also be a cause, or the absence of a comma in the JSON. Forgetting a merge variable in an order will also cause this error and many more reasons.

Be sure to check the response to see what the problem is.

400 - Bad Request

Check that all fields contain (correct) data, check the syntax. Often there is a small error in the merge variables (forgetting one).

401 - Unauthorized

This is an authentication problem, check the validity of the API Key.


A problem on Print.one's side. In most cases, it is resolved a few seconds later. Please wait a moment, try again, and otherwise contact us.

These errors are automatically reported by our systems, so our team will be made aware.