SMS delivery can be impacted by downstream provider or carrier delays or message failures, affecting critical messaging such as notifications and one-time passcodes. AWS End User Messaging now monitors sending performance in phone pools and automatically switches to the next best performing number when issues are detected.
This failover mechanism requires no user action and enhances the reliability of time-sensitive SMS communications across all supported AWS Regions. Customers using phone pools benefit from improved message deliverability and uninterrupted end-user engagement.
Source & further reading
AWS End User Messaging strengthens SMS deliverability with automatic failover ↗Source published 2026-09-14. This report was prepared with AI assistance from the linked primary-source material. Claims and limitations should be checked against the original announcement or research.