# 60364: Challenge SID invalid or not provided

Log Type: APPLICATION

Log Level: ERROR

## Description

Twilio returns this error when your Verify request does not include a valid Challenge SID. Challenge resources are used by Verify Push and Verify TOTP, and the Challenge `sid` must be a `SID<YC>` value that starts with `YC` and contains 34 characters.

### Possible causes

* The request did not include the Challenge `sid`.
* The value provided for the Challenge `sid` does not match the required format `^YC[0-9a-fA-F]{32}$`.
* The request used the SID for a different resource, such as a Service, Entity, or Factor, instead of the Challenge `sid`.
* The Challenge `sid` was truncated, altered, or stored incorrectly before the request was sent.

### Possible solutions

* Send the Challenge `sid` returned by the Challenge resource in the `sid` field.
* Validate the SID before sending the request. Use a 34-character value with the `YC` prefix.
* Confirm you are passing the Challenge SID in the correct path parameter for endpoints such as `/Services/{ServiceSid}/Entities/{Identity}/Challenges/{Sid}`.
* Verify that the Challenge SID belongs to the same Verify Service and `Identity` you are using for the request.
* If you approve challenges from your backend or client application, validate that you are sending the expected challenge SID for that action.

#### Additional resources

* [Challenge Resource](/docs/verify/api/challenge)
* [Verify Push Client Library Technical Overview](/docs/verify/push/technical-overview)
* [Verify TOTP Technical Overview](/docs/verify/totp/technical-overview)