---
set: 4
code: 407
title: Proxy Authentication Required
references:
    "Rails HTTP Status Symbol": ":proxy_authentication_required"
    "Go HTTP Status Constant": "http.StatusProxyAuthRequired"
---

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<sup>[1](#ref-1)</sup>
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<sup>[2](#ref-2)</sup>.

---

* <span id="ref-1"><sup>1</sup> Proxy-Authenticate
[RFC7235 Section 4.3][2]</span>
* <span id="ref-2"><sup>2</sup> Proxy-Authorization
[RFC7235 Section 4.4][3]</span>
* Source: [RFC7235 Section 3.2][1]

[1]: <http://tools.ietf.org/html/rfc7235#section-3.2>
[2]: <http://tools.ietf.org/html/rfc7235#section-4.3>
[3]: <http://tools.ietf.org/html/rfc7235#section-4.4>