---
set: 4
code: 407
title: Proxy Authentication Required
references:
"Rails HTTP Status Symbol": ":proxy_authentication_required"
"Go HTTP Status Constant": "http.StatusProxyAuthRequired"
"Symfony HTTP Status Constant": "Response::HTTP_PROXY_AUTHENTICATION_REQUIRED"
"Python2 HTTP Status Constant": "httplib.PROXY_AUTHENTICATION_REQUIRED"
"Python3+ HTTP Status Constant": "http.client.PROXY_AUTHENTICATION_REQUIRED"
"Python3.5+ HTTP Status Constant": "http.HTTPStatus.PROXY_AUTHENTICATION_REQUIRED"
---
Similar to [401 Unauthorized](/401), but it indicates that the client needs to authenticate itself in order to use a proxy.
The proxy MUST send a Proxy-Authenticate header field[1](#ref-1) containing a challenge applicable to that proxy for the target resource. The client MAY repeat the request with a new or replaced Proxy-Authorization header field[2](#ref-2).
---
* 1 Proxy-Authenticate
[RFC7235 Section 4.3][2]
* 2 Proxy-Authorization
[RFC7235 Section 4.4][3]
* Source: [RFC7235 Section 3.2][1]
[1]:
[2]:
[3]: