---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/80408#article
headline: "80408: Service Sid Invalid"
url: https://www.twilio.com/docs/api/errors/80408
inLanguage: en
dateModified: 2026-06-08T12:04:59.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 80408: Service Sid Invalid

Log Level: WARNING

## Description

This warning appears when a Proxy request includes a `ServiceSid` value that Twilio cannot validate as a Proxy Service identifier. Proxy Service resources use SIDs with the `KS` prefix, and Proxy endpoints use that value as the parent Service identifier.

### Possible causes

* The request did not include the required `ServiceSid` value for a Proxy endpoint that expects a parent Service resource.
* The `ServiceSid` value does not match the Proxy Service SID format. Proxy Service SIDs use the `KS` prefix and are 34 characters long.
* You may have used a different resource SID, such as a `PN` phone number SID, instead of a Proxy Service SID.

### Possible solutions

* Copy the Service SID from your Proxy Service resource and confirm that it starts with `KS` and matches the documented SID format before you send the request.
* Pass that value in the required `ServiceSid` path parameter for the Proxy resource you are calling, such as `/Services/{ServiceSid}/PhoneNumbers`.
* If you need to confirm the value, fetch the Service directly with `GET /v1/Services/{Sid}` or list your Services and use the returned Service SID in the next request.

#### Additional resources

* [Proxy API Overview](/docs/proxy/api)
* [Proxy Service resource](/docs/proxy/api/service)
* [What is a String Identifier (SID)?](/docs/glossary/what-is-a-sid)