HTTP 400 Error When Updating Webhook URL in Twilio Console – Twilio Support

Issue

When attempting to update the webhook URL for a Twilio phone number in the Twilio Console, the user receives a generic error message:

"There was an error" with an HTTP 400 status code, even though the new webhook endpoint is live and accessible.

This issue may present with the following symptoms

Unable to save or update the webhook URL in the Twilio Console.
HTTP 400 error is displayed with no additional details.
The webhook endpoint is confirmed to be publicly accessible and returns a 2xx response to GET/POST requests.
The issue does not occur when updating the webhook URL via the Twilio REST API.

Product

REST API (IncomingPhoneNumbers resource)
Webhook URL for SMS/Voice

Environment

legacy Twilio Console

Cause

This issue is typically caused by a local browser problem, such as:

Cached data or cookies interfering with the Twilio Console’s form submission.
Browser extensions or settings blocking the request.
Rarely, a temporary issue with the Twilio Console UI.

Resolution

Step 1: Verify Endpoint Accessibility

Ensure the webhook URL is publicly accessible and does not require authentication or IP whitelisting.
Confirm the endpoint returns a 2xx response to external GET/POST requests.

Step 2: Update Webhook via REST API (Recommended Workaround)

If the Twilio Console continues to show an error, update the webhook URL using the Twilio REST API:

curl -X POST "https://api.twilio.com/2010-04-01/Accounts/{AccountSid}/IncomingPhoneNumbers/{PhoneNumberSid}.json" \
--data-urlencode "SmsUrl=https://your-webhook-url" \
-u {AccountSid}:{AuthToken}

Replace {AccountSid}, {PhoneNumberSid}, and the webhook URL as appropriate.

Step 3: Browser Troubleshooting

If you prefer to use the Twilio Console:

Clear your browser’s cookies and cache.
Try using a different browser or an incognito/private browsing window.
Disable browser extensions that might interfere with form submissions.

Step 4: Collect Logs (If Issue Persists)

If the error persists, collect browser Twilio Console logs and network trace while reproducing the issue.
Share these logs with Twilio Support for further investigation.

Additional Information

Updating the webhook via the REST API is a reliable workaround.
Keeping browser cache clear and using incognito mode can prevent similar issues in the future.

The HTTP 400 error in this scenario is not due to the webhook endpoint or Twilio backend, but rather a local browser or session issue affecting the Twilio Console UI.