The four UK mobile network operators (MNOs) have confirmed to the UK Government that they do not intend to offer 2G and 3G services beyond 2033 at the latest. Individual MNOs may decide to switch off services earlier than that deadline.
All 2G and 3G only devices will need to be upgraded to at least 4G, or alternative solutions provided.
Part of our role monitoring the 2G/3G switch-off is ensuring customers, in particular vulnerable customers, do not suffer undue disruption. To do this, we are publishing relevant 2G coverage data to assist interested sectors, especially the telecare sector, which may use international roaming SIMs, in identifying where loss of indoor service may occur following changes to 2G networks. This may help indicate areas where device upgrades can be prioritised by service providers ahead of changes to 2G networks. Providers may consider using it to support work they need to carry out.
However, this data should be regarded as indicative only, and not solely relied upon for the purpose of identifying exact locations.
The data is only relevant to 2G only devices which are therefore incapable of connecting to 4G/5G and it is unrelated to 4G/5G mobile coverage.
Proposed Changes to Virgin Media O2’s (O2) 2G Network
O2 has announced it will withdraw access to its 2G and 3G networks from inbound roaming services from 1 October 2025. Sectors such as the telecare sector, which may use international roaming SIMs for their operations, could be impacted by these changes.
We are therefore publishing, with the caveat set out above, a list of postcodes containing premises that are predicted to become new '2G inbound roaming not-spots' indoors i.e. postcodes where international roaming SIMs are predicted to lose 2G indoor coverage once O2 restricts inbound roaming on its 2G network, as O2 is the only MNO providing 2G coverage at these locations. The list is computed using the indoor coverage threshold used in our Connected Nations publication. Details of the thresholds is provided in the Mobile Coverage section of the Methodology Annex to our 2024 report.
Published 17 April 2025. Data as of September 2024.
Indoor mobile signals can vary hugely in any given premises and between different premises, and reliably predicting indoor coverage is not trivial. Given the particular risks associated with telecare, we are also publishing, with the caveat set out above, a list of additional postcodes where international roaming SIMs are predicted to lose 2G indoor coverage once O2 restricts inbound roaming on its 2G network, using a more conservative approach to predicting indoor coverage than the one we use for our Connected Nations publication.
Postcodes containing premises where only O2 provides 2G coverage – using more conservative threshold
Published 17 April 2025. Data as of September 2024.
To help raise awareness, we have also published some advice for Internet of Things and third-party device suppliers in relation to 3G and 2G switch-off.
Technical notes
- The published lists of postcodes are based on mobile network operators' predictions of their 2G outdoor coverage, to which we have applied a range of additional assumptions on signal losses to help predict the likely 2G signal strength indoors.
- The data consists of postcodes where we have judged that at least one property within the postcode is affected.
- Some postcodes listed in the data do not contain ‘premises’ as defined by Ofcom in Connected Nations but are included for completeness.
- The data published is not definitive for the purpose of identifying properties that may be affected. Do not solely rely on this data. Instead, this data should be used with other potential indicators of reliable 2G mobile signal loss, to identify customers who could be affected and require support to ensure continuity of service.
Other things to note
- This data should only be used to identify existing users of 2G devices; it is not suitable for future planning or other purposes.
- The data is particularly useful to companies who use 2G international roaming SIMs to provide connectivity to their own customers. It complements the existing work UK MNOs are doing to identify third-party users of their 2G and 3G networks.