---
"@context": https://schema.org
"@type": TechArticle
"@id": https://www.twilio.com/docs/api/errors/11236#article
headline: "11236: Certificate Invalid - Certificate Expired"
url: https://www.twilio.com/docs/api/errors/11236
inLanguage: en
dateModified: 2026-06-09T11:00:42.000Z
author:
  "@type": Organization
  name: Twilio Developer Education Team
publisher:
  "@type": Organization
  name: Twilio
---

# 11236: Certificate Invalid - Certificate Expired

Log Level: ERROR

## Description

Twilio returns this error when it makes an HTTPS request to your webhook or callback URL and the endpoint presents an expired certificate. Twilio logs webhook invocation problems in the Debugger, including the request and response details for the failed webhook request.

### Possible causes

* The certificate served by your HTTPS endpoint is past its expiration date.
* Twilio is validating the HTTPS endpoint you configured for a webhook or callback URL, and that validation fails because the certificate is expired.

### Possible solutions

* Renew or replace the expired certificate for the exact hostname used by your webhook or callback URL.
* After you renew the certificate, open the webhook URL in a browser or test it with your HTTP client to confirm the endpoint no longer returns certificate errors.
* Review the Debugger or Request Inspector in Console to inspect the failing webhook request and confirm Twilio can reach the updated endpoint.

#### Additional resources

* [Webhooks security](/docs/usage/webhooks/webhooks-security)
* [Debugging your application](/docs/usage/troubleshooting/debugging-your-application)
* [Getting started with Twilio webhooks](/docs/usage/webhooks/getting-started-twilio-webhooks)