# US SMS delivery delays and failures

- Provider: [Duo Security](https://down.guide/duo)
- Level: confirmed
- Impact: Partial outage
- lasted 3h 26m
- started 2025-08-06 04:40 UTC
- SMS Message Delivery, SMS Message Delivery, SMS Message Delivery +59
- us
- id: DWN-b2deb44604
- Official page: https://stspg.io/jh3hssq7vcyf

## Updates from Duo Security
### 2025-08-06 04:40 UTC: investigating
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.

### 2025-08-06 04:49 UTC: identified
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.

### 2025-08-06 08:06 UTC: resolved
The issue affecting SMS delivery to US phone numbers has been resolved. Services are now fully operational.

---
down.guide reads providers' official status pages every minute and adds its own evidence, always labeled. Free, no account. Agents: MCP at https://down.guide/mcp, REST at https://down.guide/api/v1, feeds at https://down.guide/feed. Built by Sazabi (https://sazabi.com/?utm_source=down-guide&utm_medium=markdown).