In a move to streamline its network operations, VM02 (Virgin Media O2) has announced that, starting October 1, 2025, the O2 UK 2G and 3G networks will no longer be accessible to inbound roaming service providers. This means multi-network SIMs from non-O2 providers will lose access to these legacy networks. Please note that all Alarm Signalling Devices have been assessed, and if this impacts you, you have already been contacted.
As all other UK mobile networks have already decommissioned their 3G services, this change effectively marks the end of 3G connectivity for all customers using multi-network SIMs in the UK. However, devices may still connect to EE and Vodafone 2G networks where available, with both providers indicating their 2G networks will remain active until later in the decade—though this is subject to change.
Devices capable of 4G connectivity will continue to access O2, EE, Vodafone, and Three UK’s 4G networks.
To help you understand the changes in more detail, we have prepared the following FAQs:
Frequently Asked Questions (FAQs)
When is this change happening?
1st October 2025.
Why is this change happening?
Network operators continuously optimise their roaming partnerships and network configurations. Removing O2 UK 2G/3G roaming is part of efforts to prioritise modern network technologies (4G, 5G) and ensure reliable, future-proof connectivity.
What is changing with O2 UK 2G / 3G network access?
All multi-network roaming services in the UK will no longer include the O2 UK 2G network. This means devices with roaming SIMs will no longer be able to connect to the O2 UK 2G network.
Is O2 UK shutting down its entire 2G network?
Not yet. Virgin Media O2 (VMO2), like all UK mobile network operators, is beginning the process of “sunsetting” its 2G network ahead of the OFCOM-mandated closure in 2032. This phased approach allows spectrum to be reallocated for newer technologies such as 4G and 5G. CSL will continue to keep you informed as further changes are announced that may affect your service.
Is O2 UK shutting down its entire 3G network?
Virgin Media O2 (VMO2) is the last UK mobile network operator still operating a 3G service. The shutdown of its 3G network is already underway, with regional switch-offs having started in April 2025. From 1st October 2025, O2 UK will also withdraw inbound 3G roaming, and the entire 3G network will be fully decommissioned by the end of 2025.
Will this affect my devices?
That depends on the type of devices you’re using:
- Devices with only 2G or 3G capability:
- These may lose service in areas where they relied solely on O2 UK 2G for coverage and are unable to access EE or Vodafone 2G services. We recommend planning to upgrade to 4G-capable devices.
- 4G-capable devices currently using O2 UK 2G:
- These devices can continue to operate but may need configuration updates to prioritise other networks or 4G service to avoid connection issues.
What if I have a few devices on O2 UK 2G or 3G and mostly 4G-capable devices:
Impact is expected to be minimal, but it’s good practice to verify all devices are configured correctly.
How do I check if my devices will be affected?
We recommend reviewing your device inventory:
- Check the network capabilities (2G, 3G, 4G, 5G).
- Work with CSL to review usage patterns, especially in locations where O2 2G was the fallback option.
- Identify any 2G/3G-only devices that will need replacing due to an inability to access EE or Vodafone 2G services.
If you need help assessing your devices, our team can assist with audits and recommendations.
What should I do if I have devices that only support 2G or 3G?
We strongly recommend beginning planning an upgrade to 4G-capable devices. Without this, these devices may lose connectivity in areas where O2 2G/3G was the only available network.
Our team can support you with:
- Device audits
- Replacement recommendations
- Migration planning
How can I prepare if I have 4G-capable devices using O2 UK 2G/3G?
If your devices are 4G-capable but currently using O2 2G/3G, you may just need to update their network settings:
- Prioritise 4G connectivity in device profiles.
- Test devices in key operating locations.
- Schedule configuration updates if needed.
We’re happy to help guide you through this process.
Will this change affect other networks or services?
No. Other UK networks and technologies (4G, 5G) remain available in our roaming profile. This change only affects access to the O2 2G/3G network specifically.
How can I get help or more information?
Our team is here to support you if you have questions or need assistance. We’ll be happy to help you review your devices, plan upgrades, or manage any required updates to keep your services running smoothly.
