509 Bandwidth Limit Exceeded

Shared hosting code indicating the account exceeded its allotted bandwidth for the billing period.

Status

HTTP/1.1 509 Bandwidth Limit Exceeded

Details

Category: 5xx
Status: Unofficial (Apache (bw/limited extension), cPanel). Not registered with IANA. A server, framework, or CDN convention.
Specification: none, not defined by any RFC
Cacheable: Not cacheable
Response body: Allowed
Retry: Do not retry

509 is emitted by the bandwidth limit module used in cPanel and similar shared hosting control panels. The site is suspended for the rest of the period, or until the operator raises the allowance.

It is not in the IANA registry and no standard defines it. It is common enough on budget hosting that most operators recognize it on sight.

Common causes

A hosting account exhausted its monthly transfer allowance.
A traffic spike, hotlinked assets, or a scraper consuming the allowance early in the cycle.

How to fix it

As the client

Stop retrying. The limit resets on the host's billing cycle, not on a timer you control.

As the server

Raise the plan allowance or move heavy assets to a CDN or object storage.
Block hotlinking and cache aggressively so bandwidth is spent on real visitors.

Examples

GET / HTTP/1.1
Host: small-site.example.com

HTTP/1.1 509 Bandwidth Limit Exceeded