> ## Documentation Index
> Fetch the complete documentation index at: https://www.plain.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Allowlist the IP addresses Plain sends requests from

> The fixed IP addresses Plain sends webhooks, customer card requests, and workflow HTTP requests from.

Plain sends [webhooks](https://www.plain.com/docs/webhooks.md), [customer card](https://www.plain.com/docs/customer-cards.md) requests, and [workflow HTTP requests](https://www.plain.com/docs/product/workflows/workflows-actions.md#send-http-request) from fixed IP addresses, one set per region. Allowlist the addresses for your workspace's region at your firewall or API gateway so your endpoint only accepts these requests from Plain.

## IP addresses for the UK region

For workspaces in Plain's UK region, hosted in AWS `eu-west-2` (London), Plain sends requests from these addresses. Allow all of them, since any request can come from any address in the list:

<Snippet file="shared/outbound-ip-addresses-uk.mdx" />

Other requests Plain makes, such as fetching knowledge sources or calling MCP servers, come from addresses Plain doesn't publish.

## Keep verifying requests from Plain

Every workspace in a region sends from the same addresses, so anyone can point their own webhook target at your URL and pass the allowlist. Keep verifying requests with [request signing](https://www.plain.com/docs/request-signing.md) or [mTLS](https://www.plain.com/docs/mtls.md): the allowlist adds to them and doesn't replace them.


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