US SMS delivery delays and failures

What to do

• Check whether you use Duo Security SMS Message Delivery, SMS Message Delivery, SMS Message Delivery, SMS Message Delivery and 58 more in us. Check your stack

  Paste a package.json, lockfile, Terraform or a list of domains at down.guide/stack to see every provider you depend on.

• Confirm your retries, queues and scheduled jobs caught up after the 3h 26m it lasted.

  Anything that failed between 2025-08-06 04:40 UTC and 2025-08-06 08:06 UTC may need a replay.

• Subscribe to Duo Security's feed to hear about the next one first. RSS feed

  https://down.guide/feed?provider=duo works in Slack (/feed subscribe), Discord feed bots and any RSS reader.

Updates from Duo Security 3

1. investigatingAug 6, 2025, 4:40 AM UTC

   We are investigating an issue causing SMS delivery delays and failures in the US. We are waiting for AT&T to fix the issues on their end. During this time, please use alternate authentication methods such as Duo Push, Duo Mobile Passcodes, Hardware Tokens etc to login to your Duo-protected integrations.

   provider

2. identifiedAug 6, 2025, 4:49 AM UTC

   We have identified an issue causing SMS delivery delays and failures in the US. We are waiting for AT&T to fix the issues on their end. During this time, please use alternate authentication methods such as Duo Push, Duo Mobile Passcodes, Hardware Tokens etc to login to your Duo-protected integrations.

   provider

3. resolvedAug 6, 2025, 8:06 AM UTC

   The issue affecting SMS delivery to US phone numbers has been resolved. Services are now fully operational.

   provider

Corrections

None so far.

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