# Duo Phone Call Authentication Failures - United States

- Provider: [Duo Security](https://down.guide/duo)
- Level: confirmed
- Impact: Degraded
- lasted 2h 54m
- started 2026-08-08 21:13 UTC
- Phone Call Delivery, Phone Call Delivery, Phone Call Delivery +45
- us
- id: DWN-e244d1b902
- Official page: https://stspg.io/7d70dz419kvq

## Updates from Duo Security
### 2026-08-08 21:13 UTC: identified
We have identified an issue causing phone call authentication failures for customers in the United States. This is related to a third-party carrier disruption. We are actively monitoring the carrier issue and working with our provider as needed.
Please check back here or subscribe to updates for any changes.

### 2026-08-08 23:04 UTC: monitoring
We are seeing recovery for the issue related to a third-party carrier disruption that caused phone call authentication failures for customers in the United States.
We are actively monitoring phone call authentication delivery and will provide another update once the issue is fully resolved.

### 2026-08-09 00:07 UTC: resolved
Phone call authentication delivery for customers in the United States has returned to normal operation.
If customers continue to experience issues, please contact Duo Support.

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