Outage in Cisco Duo

T-Mobile Services SMS Delivery Issue

Resolved Minor
August 26, 2025 - Started 4 days ago - Lasted about 4 hours
Official incident page

Need to monitor Cisco Duo outages?
Stay on top of outages with IsDown. Monitor the official status pages of all your vendors, SaaS, and tools, including Cisco Duo, and never miss an outage again.
Start Free Trial

Outage Details

We are currently investigating an issue affecting SMS delivery to phone numbers using T-Mobile Services in the US. Please feel free to check back here or subscribe to updates for the latest information regarding any changes or resolutions.
Components affected
Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery Cisco Duo SMS Message Delivery
Latest Updates ( sorted recent to last )
RESOLVED 3 days ago - at 08/26/2025 10:21AM

Duo has confirmed that the issue affecting SMS delivery to phone numbers using T-Mobile services in the US has been fully resolved.

MONITORING 3 days ago - at 08/26/2025 08:14AM

We are starting to see recovery post the fix implemented by our service provider for the issue affecting SMS delivery to phone numbers using T-Mobile Services in the US.

Please feel free to check back here or subscribe to updates for the latest information regarding any changes or resolutions.

IDENTIFIED 3 days ago - at 08/26/2025 08:02AM

We have detected the issue affecting SMS delivery to phone numbers using T-Mobile Services in the US.
Please feel free to check back here or subscribe to updates for the latest information regarding any changes or resolutions.

INVESTIGATING 4 days ago - at 08/26/2025 06:29AM

We are currently investigating an issue affecting SMS delivery to phone numbers using T-Mobile Services in the US.

Please feel free to check back here or subscribe to updates for the latest information regarding any changes or resolutions.

Latest Cisco Duo outages

Blank Duo Prompt issue impacting users authenticating from both Chrome and Edge version 136 browsers and Epic Hyperdrive - about 1 hour ago
[Multiple Deployments] - Issues with User Management in Admin Panel - 3 days ago
Admin functions impacted when accessing Users and AD Sync on certain deployments - 3 days ago
India VoIP Failures - 11 days ago
US SMS delivery delays and failures - 24 days ago

Be the First to Know When Vendors Go Down

With IsDown, you can monitor all your critical services' official status pages from one centralized dashboard and receive instant alerts the moment an outage is detected. Say goodbye to constantly checking multiple sites for updates and stay ahead of outages with IsDown.

Start free trial

No credit card required · Cancel anytime · 4400 services available

Integrations with Slack Microsoft Teams Google Chat Datadog PagerDuty Zapier Discord Webhook