Duo Security experienced a major incident on July 24, 2025 affecting Phone Call Delivery and Phone Call Delivery and 1 more component, lasting 10h 48m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Jul 24, 2025, 01:44 PM UTC
We are currently investigating an issue caused by our UK telephony providers regarding VoIP failures with Duo on DUO70 and are working to correct the issue as soon as possible. Please check back here or subscribe to updates for any changes.
- investigating Jul 24, 2025, 01:55 PM UTC
We are currently investigating an issue caused by our UK telephony providers regarding VoIP failures with Duo on DUO70 and are working to correct the issue as soon as possible. Please check back here or subscribe to updates for any changes.
- identified Jul 24, 2025, 02:25 PM UTC
We have identified the cause of the VoIP authentication failures in Great Britain and our telephony providers in the region are actively working to restore service. While we are monitoring this, please use alternate authentication methods such as Duo Push, Duo Mobile Passcodes, Hardware Token etc. to login to your Duo-protected integrations.
- monitoring Jul 24, 2025, 03:04 PM UTC
We are actively monitoring the VoIP phone call authentication issue affecting Great Britain.
- identified Jul 24, 2025, 05:27 PM UTC
We're continuing to partner with our telephony providers in the region as they work to restore service. Please use alternate authentication methods such as Duo Push, Duo Mobile Passcodes, Hardware Token etc. to login to your Duo-protected integrations until the issue has been resolved.
- monitoring Jul 24, 2025, 11:02 PM UTC
The issue causing VoIP authentication failures in Great Britain appear to be resolved. We are continuing to monitor the situation closely and will post any updates when the incident is considered fully resolved.
- resolved Jul 25, 2025, 12:43 AM UTC
The issue causing VoIP authentication failures in Great Britain is now resolved.