ONSIM experienced a notice incident on July 14, 2026 affecting Voice and Data and 1 more component, lasting 2d 4h. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- identified Jul 14, 2026, 07:52 AM UTC
We are currently aware of an issue affecting some customers' mobile services. Our upstream carrier is aware of the issue and their engineers are currently working on a resolution. We are in regular contact with them and will continue to provide updates as soon as we receive further information. At this time, we do not have an estimated time for resolution. We apologise for the inconvenience and appreciate your patience while the issue is being resolved.
- identified Jul 14, 2026, 08:02 AM UTC
We are continuing to work on a fix for this issue.
- identified Jul 14, 2026, 09:42 AM UTC
Our upstream carrier continues to investigate the issue affecting a number of customers. Their engineers remain actively engaged in identifying the cause and restoring full service. Although there is no estimated time for resolution at present, we will update this page as soon as we receive any significant new information. For customers with Wi-Fi Calling enabled, calls and texts should continue to work as normal when connected to a Wi-Fi network. Customers can also log in to the Onsim Dashboard (https://app.onsim.uk/) to apply call diverts if required, helping to minimise disruption while the issue is being resolved. Thank you for your continued patience while work to resolve the issue continues.
- identified Jul 14, 2026, 10:42 AM UTC
Our upstream carrier continues to work on the incident, with engineering teams actively investigating the underlying cause and implementing corrective measures. Efforts to restore service are ongoing and we are maintaining close communication with the carrier and will publish further updates as soon as there is confirmed progress to report. Customers with Wi-Fi Calling enabled can continue to make and receive calls and text messages when connected to Wi-Fi. If required, call diverts can also be configured via the Onsim Dashboard (app.onsim.uk) to help minimise disruption. We recognise the inconvenience this incident is causing and sincerely appreciate your continued patience and support while work continues to restore all services.
- identified Jul 14, 2026, 11:42 AM UTC
We are continuing to work with our network partner as they investigate the service disruption currently affecting some customers. Their technical teams remain engaged and are working to identify the underlying cause and restore normal service. We are maintaining regular contact with them and are continuing to monitor progress closely. We appreciate that some customers have now been impacted for an extended period and understand the importance of receiving clear information. Unfortunately, we do not currently have a confirmed timeframe for when full service will be restored. Customers with Wi-Fi Calling enabled can continue to make and receive calls and text messages when connected to Wi-Fi. If required, call diverts can also be configured via the Onsim Dashboard (app.onsim.uk) to help minimise disruption. Further updates will be provided as soon as we have additional information to share. Thank you for your continued patience and understanding.
- identified Jul 14, 2026, 12:43 PM UTC
Our upstream carrier has identified that a recent routing change may be contributing to the ongoing service disruption. While the root cause has not yet been fully confirmed, they are actively working to roll back this change as part of their investigation. At the same time, we are working alongside their engineering teams on an alternative workaround that may restore service for some affected customers while the investigation continues. We will provide a further update as soon as we have more information on the progress of either approach. Customers with Wi-Fi Calling enabled can continue to make and receive calls and text messages when connected to Wi-Fi. If required, call diverts can also be configured via the OnSim Dashboard (app.onsim.uk) to help minimise disruption. Our service status page is updated hourly and remains the best place to find the latest information: https://status.onsim.uk/ Customers can also subscribe to the status page to receive notifications whenever new updates are published. Thank you for your continued patience and understanding.
- identified Jul 14, 2026, 01:48 PM UTC
There is no further update to share at this time. Our upstream carrier continues to investigate the issue and progress the work previously outlined. We remain in regular contact with their engineering teams and are continuing to monitor the situation closely. Customers with Wi-Fi Calling enabled can continue to make and receive calls and text messages when connected to Wi-Fi. If required, call diverts can also be configured via the OnSim Dashboard (app.onsim.uk) to help minimise disruption. Our service status page is updated hourly and remains the best place to find the latest information: https://status.onsim.uk/ Customers can also subscribe to the status page to receive notifications whenever new updates are published. Thank you for your continued patience and understanding while work continues.
- identified Jul 14, 2026, 02:51 PM UTC
We have no new updates to share at this time. Our upstream carrier is actively investigating the issue and progressing with the fixes previously outlined. We remain in constant contact with their engineering teams and are continuing to monitor the situation closely. In the meantime, customers with Wi-Fi Calling enabled can continue to make and receive calls and text messages normally when connected to Wi-Fi. If required, call diverts can also be configured via the OnSim Dashboard (app.onsim.uk) to help minimize any disruption to your service. For the latest details, please check our Service Status Page (status.onsim.uk), which is updated hourly. You can also subscribe directly on that page to receive automatic alerts whenever a new update is published. Thank you for your continued patience and understanding while this work is underway.
- identified Jul 14, 2026, 03:45 PM UTC
Our carrier is still working through the resolution steps previously mentioned and investigating the root cause. We are staying in close communication with their technical teams and continue to monitor their progress around the clock. While this is being resolved, you can still use Wi-Fi Calling to make or receive calls and texts as normal, provided you are connected to a Wi-Fi network. Additionally, you can set up call forwarding through the OnSim Dashboard (app.onsim.uk) to help minimize any disruption to your service. For real-time progress reports, please monitor our Service Status Page (status.onsim.uk), which we update every hour. You can also sign up for automatic notifications directly on that page to get alerts the moment new information is published. We really appreciate your ongoing patience and understanding while this work is being carried out.
- monitoring Jul 14, 2026, 07:19 PM UTC
Update on today's service incident: The cause has been narrowed to a routing change made by an upstream carrier partner. A mitigation was implemented this evening and has resolved the registration issues for users connecting over 4G/VoLTE. Service for the majority of users should now be back to normal. A very small number of users may still be affected. This will be users connecting over 2G circuit-switched rather than VoLTE. We have a workaround for this and can apply it on an individual basis. If you are still experiencing problems, please contact us at [email protected] and we will assist you with implementing this workaround on your device. We will continue to monitor closely, and we have requested a written Root Cause Analysis from our carrier partner. Live updates remain at status.onsim.uk. Our sincerest apologies for the disruption caused by this incident — we know how much of a problem this causes for our customers and did everything in our power to restore service as quickly as possible.
- monitoring Jul 15, 2026, 12:40 PM UTC
Our Upstream Carrier has made changes that has dramatically improved services beyond the previously announced mitigations. We continue our evaluation but believe that service has been fully restored across all Home Countries. The Mitigation Steps taken to restore services will also remain in place and the situation is being monitored closely.
- monitoring Jul 15, 2026, 04:39 PM UTC
We are continuing to monitor for any further issues.
- resolved Jul 16, 2026, 02:14 PM UTC
Following extensive repetitive testing and enhanced monitoring we are seeing no further registration delays and all users service experience is returned to normal.