Reserved for future use. The original intention was that this code might be used as part of some form of digital cash or micropayment scheme.
What does HTTP 402 mean?
The 402 Payment Required code is part of the 4XX class. This is a client error code — the request was faulty, unauthorized, or cannot be fulfilled. The problem is on the request side.
When is it used?
A server returns 402 Payment Required in situations matching the definition above. You will encounter it inspecting network requests, reading logs, or testing an API. Whether it signals a problem depends on its class: 2xx and 3xx are normal, while 4xx and 5xx usually need attention on the client or server respectively.