Between 10:29 AM UTC and 2:59 PM UTC on July 2, calls made through Twilio phone numbers experienced failures due to a recent update, leading to customers reaching call capacity and encountering 429 errors. SIP phone numbers using Twilio SIP Trunks were unaffected.

The problematic update was rolled back at 12:54 PM UTC, stopping new failures. Full call capacity was restored by 2:59 PM UTC. We are implementing improved testing, telemetry, and monitoring to prevent recurrence and enhance response times.

We've rolled back our latest release, and the system seems to be holding steady, which indicates a faulty release. We're still investigating the main cause of the issue, but we have a good idea of what it is.

We've identified the cause of the outage and are working on finding a resolution. We'll likely roll back as we investigate.