O2 3G Shutdown 2025-2026: Dates, Affected Phones & How to Check

O2 is turning off its 3G network across the UK, and if you have an older phone, your service could be about to change; the switch‑off began in 2025 and is expected to be largely complete by early 2026, freeing up spectrum for faster 4G and 5G. Here’s what you need to know to check your phone, upgrade your SIM if needed, and stay connected.

O2 3G shutdown started: 2025 · Mostly complete by: March 2026 · 3G traffic share before shutdown: Less than 1% · Customers affected: Undisclosed (still migrating to 4G/5G)

Four quick facts that set the stage for the switch‑off.

What date is O2 turning off 3G?

O2 began switching off its 3G network in phases during 2025. According to the O2 official guidance, most of the 3G network is already off across the UK. Some areas may still pick up a 3G signal during the early part of 2026, but the end is near.

Has O2 already turned off 3G in my area?

If you haven’t lost 3G signal yet, it’s likely you live in one of the later‑phase regions. O2’s own Virgin Media O2 News statement confirmed in December 2025 that the shutdown would be completed in “the coming weeks.”

When will the remaining 3G signal be switched off?

O2’s help page currently says: “Most of our 3G network has now been switched off across the UK, but some areas may still get a 3G signal during the early part of 2026.” The implication: by mid‑2026 any remaining 3G signal will vanish.

How do I check if my phone will work after a 3G shutdown?

You can verify compatibility in a few minutes without any technical knowledge. The key is whether your handset supports 4G LTE and Voice over LTE (VoLTE).

How to test if your phone supports 4G VoLTE

On Android: go to Settings → Mobile networks → VoLTE (the label may vary). On iPhone: Settings → Cellular → Voice & Data → 4G (VoLTE). If the option is present and enabled, you’re good. O2 recommends checking the list on its official help page.

What settings to check on an Android or iPhone

• Android: look for “Enhanced 4G LTE Mode” or “VoLTE” – if missing, the phone may not support it.
• iPhone 6 or later: generally supports 4G VoLTE; iPhone 5 and earlier do not.
• Any device bought before 2016: likely lacks 4G VoLTE and may stop making voice calls after shutdown.

If you can’t find the setting, try dialing *#*#4636#*#* (Android) to see phone info, or use an app like “Network Signal Info.”

Can I still use my phone without 3G?

It depends entirely on your handset’s capabilities.

What happens to calls and texts on a 3G‑only phone?

Phones that are 3G‑only will lose all mobile service – calls, texts and data – once O2’s 3G network is gone in that area. For devices that support 4G but not VoLTE, voice calls will stop, but data (via 4G) may still work temporarily (Virgin Media O2 News).

Can I still use data without 3G?

If your phone is 4G‑capable and configured correctly, you’ll get 4G data. If it’s 3G‑only, data becomes impossible. O2’s own statement warns: “If you do not upgrade before 3G is switched off in your area, you will still be able to make calls and send text messages, but not use mobile data” – that applies only to phones that can fall back to 2G for voice, but for 3G‑only devices all services stop (Virgin Media O2 News).

Which phones will be affected by the 3G shutdown?

The real‑world impact hits older handsets. O2 hasn’t published an official “doomed list,” but the pattern is clear.

List of known affected O2 phone models

• iPhone 5, 5C – no 4G VoLTE, no 4G at all
• Samsung Galaxy S4, S5 – S4 is 3G‑only; S5 lacks VoLTE on O2
• HTC One M8 – no VoLTE support
• Budget Android phones from 2013‑2015 – most lack 4G VoLTE

Any phone released before 2016 that doesn’t have 4G VoLTE is at risk. Phones from 2016 onward almost always support it.

Will iPhone 6 or Samsung Galaxy S5 work after shutdown?

iPhone 6 (released 2014) does support 4G VoLTE – it should work. Samsung Galaxy S5 (2014) supports 4G but not VoLTE on O2 – it will lose voice calls. Mobile Signal Boosters Shop lists these as models that may fail.

Do I need a new SIM card to go from 3G to 4G?

Not every old SIM works on 4G. O2 says customers may need a SIM upgrade.

How to check if your SIM card is 4G‑compatible

Go to Settings → About phone → Status → SIM status (Android) or Settings → About → Carrier (iPhone). If you see “4G” or “LTE” next to the network type, the SIM is compatible. Otherwise, request a replacement.

Does O2 provide free SIM replacements?

Yes. O2 offers free SIM replacements for customers moving to 4G/5G – call the O2 customer service number 0800 977 7777 or visit an O2 store. The new SIM will usually arrive within 48 hours and comes with instructions to activate 4G VoLTE (O2 help page – official policy).

Step‑by‑step: how to prepare your phone for the O2 3G shutdown

1. Check your phone’s 4G VoLTE support – use the settings method above.
2. Enable 4G Calling – turn on VoLTE in mobile network settings.
3. Test your SIM – look for 4G indicator in SIM status.
4. Request a free SIM replacement from O2 if needed.
5. If your phone is not compatible: visit an O2 store to discuss upgrade options. Virgin Media O2 says “people with 3G‑only handsets should visit a local store or call to upgrade as soon as possible” (Virgin Media O2 News).

The catch: Even with a compatible phone, if you haven’t enabled VoLTE you’ll still lose voice calls. The setting is not always on by default.

O2 3G switch‑off timeline

• 2025 – O2 begins phased switch‑off; first area Durham (2 April 2025); Norwich, Telford, Guildford, Torquay switched off July–August 2025 (Mobile Signal Boosters Shop)
• December 2025 – Virgin Media O2 confirms shutdown “to be completed in the coming weeks” (Virgin Media O2 News)
• Early 2026 – Most of O2’s 3G network now switched off; some areas may still have signal (O2 help page)

Why this matters: The pace has quickened. By March 2026, O2’s help page states “Most of our 3G network has now been switched off across the UK” – a clear signal that remaining pockets will disappear within months.

What we know and what remains unclear

Confirmed facts

• O2 3G network largely turned off by March 2026 (O2)
• Phones without 4G VoLTE will lose voice calling (Virgin Media O2 News)
• Free SIM replacement available from O2 (O2 help page)
• 2G network remains for emergency calls and some IoT (Workflo Solutions)

What’s unclear

• Exact date when all remaining 3G signals will disappear in each location
• Full official list of incompatible phone models (not published by O2)
• Whether O2 will offer free upgrades for 3G‑only devices (no official policy announced)

Voices from the switch‑off

“Most of our 3G network has now been switched off across the UK, but some areas may still get a 3G signal during the early part of 2026.”

— O2 help page (official O2 statement)

“So long, farewell, 3G, thanks for the memories. People with 3G‑only handsets should visit a local store or call to upgrade as soon as possible.”

— Virgin Media O2 press release (Virgin Media O2 News)

For O2 users in the UK, the decision is clear: check your phone’s 4G VoLTE support now. If it works, enable the setting. If it doesn’t, upgrade your handset or get a free SIM from O2. The 3G network is largely gone, and the few remaining signals will disappear by mid‑2026. Waiting will only leave you without service.

While O2 is phasing out its 3G network, the Vodafone UK 2G shutdown timeline offers a parallel look at another UK operator’s plans.

Frequently asked questions