405 Method Not Allowed

The resource exists but does not support this method. Sent with an Allow header listing the methods that do work.

What to do

The URL exists, but not for this method, such as a POST to a page that only takes GET. The Allow header lists the methods it does take.

Class
4xx Client Error. The request has a fault, or cannot be met as sent.
Registered
Yes, in the IANA HTTP status code registry.
Cacheable by default
Yes. A cache may store it without Cache-Control or Expires saying to.
References
RFC 9110 ยง15.5.6 · MDN

Example response

HTTP/1.1 405 Method Not Allowed
Allow: GET, HEAD

Every 4xx code

All HTTP status codes, in one table