Optus SMS incident
Messages using Sender IDs (Alpha Masks) to non-Australian destinations being Blocked
Optus SMS experienced a minor incident on July 28, 2026 affecting Rest of the World, lasting 2h 9m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Jul 28, 2026, 09:43 PM UTC
We are aware of an issue with the handling of messages using Sender IDs (alphanumeric masks) to international (non-Australian) destinations. Some messages, sent to non-Australian mobile numbers, using a Sender ID like 'Name' rather than a MSISDN like +614######## are currently being blocked, our Dev team are investigating and a further update will be posted in 30 minutes. Regards, Optus SMS Support Team
- monitoring Jul 28, 2026, 10:52 PM UTC
Our Development team has identified the root cause of the issue, and we are now seeing previously affected masked messages to non-Australian destinations being delivered successfully. Our team continues to monitor and work through the remaining impact to ensure all traffic is flowing normally and to prevent a recurrence of the issue. Any messages that were affected and are still required will need to be resent. Regards, Optus SMS Support Team
- resolved Jul 28, 2026, 11:52 PM UTC
We are pleased to confirm that this issue has now been resolved. Since our last update, we have observed all traffic using registered Sender IDs to international destinations flowing successfully. If you are still experiencing issues with valid messages being blocked, please contact our Support team for assistance. Regards, Optus SMS Support Team