Outage in Duo Security

T-Mobile Services SMS Delivery Issue

Resolved Minor
August 26, 2025 - Started about 2 months ago - Lasted about 4 hours
Official incident page

Incident Report

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
Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery Duo Security SMS Message Delivery

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Latest Updates ( sorted recent to last )
RESOLVED about 2 months 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 about 2 months 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 about 2 months 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 about 2 months 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.

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