---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/80403#article
headline: "80403: Interaction Sid Invalid"
url: https://www.twilio.com/docs/api/errors/80403
inLanguage: en
dateModified: 2026-06-08T12:04:59.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 80403: Interaction Sid Invalid

Log Level: WARNING

## Description

This warning appears when you send a Proxy request with an invalid Interaction SID. In Proxy, Interactions are read-only communication logs within a Session, and each Interaction SID must be a Twilio-generated value that matches the `KI` SID pattern.

### Possible causes

* The `Sid` value in your request is not a valid Interaction SID format. Proxy Interaction SIDs must match the `KI` pattern and be 34 characters long.
* You used a different Proxy SID type in place of an Interaction SID, such as a Service SID with the `KS` prefix, a Session SID with the `KC` prefix, or a Participant SID with the `KP` prefix.
* The Interaction SID was copied incorrectly, truncated, or includes extra characters, which makes it fail Proxy SID validation.
* You are trying to fetch or delete an Interaction without using the correct Proxy resource path for `ServiceSid`, `SessionSid`, and `Sid`.

### Possible solutions

* Use the Interaction `sid` returned by Proxy instead of constructing the value yourself. Twilio creates the unique SID for each Interaction resource.
* Validate that the Interaction SID starts with `KI` and matches the expected 34-character format before sending the request.
* For fetch or delete requests, send the Interaction SID in the `/Services/{ServiceSid}/Sessions/{SessionSid}/Interactions/{Sid}` path and confirm that the parent `ServiceSid` and `SessionSid` are valid Proxy SIDs for the same resource hierarchy.
* If you are not sure which Interaction SID to use, list the Session's Interactions first and then retry the request with the returned `sid` value.

#### Additional resources

* [Interaction resource](/docs/proxy/api/interaction)
* [The Proxy API Overview](/docs/proxy/api)
* [Proxy Quickstart](/docs/proxy/quickstart)