About the Unzer API

The Unzer API connects your business to the Unzer payment infrastructure.

REST architecture

The Unzer API is based on the representational state transfer (REST) architectural style.

HTTP requests

You can make requests to the Unzer API resources with standard HTTP methods.

JSON payloads

The Unzer API sends a response with a JSON payload that contains detailed information about the requested resource.

HTTP basic authentication

The Unzer API uses HTTP basic authentication (BA) over HTTPS, with your API key serving as a username.

Read more about authentication

UTF-8 encoding

The Unzer API supports only UTF-8 characters.

Sandbox environment

Use our sandbox environment to safely test your interaction with the Unzer API.

Read more about testing

Free sandbox environment
Requests made with your sandbox API keys never affect real payment networks and are never billed by Unzer.

Error codes

The Unzer API errors are indicated by HTTP response codes.

Read more about error handling

Integration options

To let you quickly implement a variety of payment stolutions into your system, we offer a whole range of integration solutions and materials:

Base URL

The main URL for the Unzer API is:


API versioning

The current version of the Unzer API is:

  • 1.0

When we release a new API version with backward-incompatible changes, we keep the previous API versions still available.