O2 Mobile Review

O2 has operated a UK mobile network since 2002, when BT Cellnet took the O2 name, and since 2021 it has been part of Virgin Media O2, a 50:50 joint venture between Liberty Global and Telefónica. The O2 network also carries giffgaff, Tesco Mobile and Sky Mobile, so many people use O2 masts without ever holding an O2 SIM.

2026 has been a busy year for the network. O2 finished switching off 3G, launched a satellite service for places with no signal and took its standalone 5G to most of the UK. It also put up the yearly price rise for customers already in contract, which led to a sharp jump in complaints. To weigh O2 against other networks on price, our mobile comparison lists current phone and SIM only deals.

We based this review on O2’s published terms, Ofcom figures and the latest independent network tests, not on our own speed tests.

O2 network features

O2 had the best overall coverage experience in Opensignal’s latest UK report, offers standalone 5G at no extra cost and includes roaming in its Europe Zone on pay monthly and pay as you go. The trade off is speed. Its typical download speeds trail EE in every national test, its performance drops in Wales and the South West of England, and its pay monthly airtime goes up by a fixed amount every April.

Suitable for

• People who travel in Europe, as roaming in O2’s Europe Zone is included on pay monthly, pay as you go and the Essential Plan.
• Anyone who values a signal in more places over top speed, as O2 won Opensignal’s Coverage Experience award.
• Virgin Media broadband customers, who get double mobile data and wider roaming through Volt.
• Walkers, drivers and farm workers in remote areas with a compatible phone, through O2 Satellite.
• Phone buyers who want to choose their upfront cost and spread the rest over a long device plan.

Less suitable for

• People who want the fastest everyday speeds. O2 had the slowest average download speed in Opensignal’s latest report and the lowest score in Ofcom’s 2026 Mobile Matters study.
• Users in Wales and South West England, where O2 users found a 5G signal far less often than EE users.
• Mobile gamers. O2 scored lowest of the four networks for Games Experience in Opensignal’s report.
• Anyone who wants a monthly price that stays the same, as airtime rises every April.

Pros and cons

Network and coverage

O2 says its 4G network reaches 99% of the UK population outdoors. Indoor signal can be much weaker, so the result at your own home and workplace matters more than any national figure.

In Opensignal’s report for October to December 2025, O2 kept the Coverage Experience award with 9.0 points out of 10, just ahead of EE on 8.8. This score looks at signal across the places people live, work and travel. O2 users had a connection 98% of the time, which put the network third on that measure.

Ofcom’s 2026 Mobile Matters study, based on Opensignal data from August 2025 to July 2026, looked at connection quality rather than reach. O2 gave a good quality connection 77% of the time, the lowest of the four networks, with results ranging from 65% in Wales to 80% in Northern Ireland. In short, O2 finds a signal in many places, but that signal often delivers less than its rivals do.

Investment and spectrum

Virgin Media O2 is in its second year of a large mobile upgrade plan, focused on reliability, capacity and 5G. It has more than 500 high capacity Giga Sites, and in October 2026 it reported that an AI based radio trial at London Paddington raised spectral efficiency by up to 20%. It has also agreed to buy 78.8MHz of spectrum from VodafoneThree, which takes its share of UK mobile spectrum to about 30%. More spectrum should help O2 close the speed gap over time.

3G gone, 2G until 2029

O2 was the last UK network to switch off 3G, with the final areas closing in early 2026. Unlike Three, O2 still has a 2G network, which it plans to start switching off in summer 2029. A phone that cannot make 4G calls can still call and text over 2G on O2 for now, but it will get very slow data. A phone that only works on 3G no longer works on O2.

O2 Satellite

In February 2026, O2 became the first UK network to launch a satellite to mobile service, using Starlink’s Direct to Cell satellites. When there is no O2 signal, a compatible phone connects to a satellite automatically and the network name changes to O2 Satellite. It supports data for selected apps, such as WhatsApp, Messenger, Google Maps, Apple Maps, weather apps and location sharing. Normal calls and standard texts do not work over satellite yet, and it works best outdoors with a clear view of the sky.

It works on recent Samsung Galaxy S and Z models and, since May 2026, on the iPhone 13 and later models. O2 says the service raises its land coverage from 89% to 95% of the UK. It comes as a monthly bolt on for pay monthly customers or is included with Ultimate plans.

Before you switch, check your postcode on Ofcom’s coverage checker. If the signal drops inside your home, our guide shows how to improve indoor signal.

5G and speeds

5G is included on all O2 pay monthly and pay as you go plans at no extra cost. You need a 5G phone and 5G signal where you are.

5G+ standalone

O2 calls its standalone 5G network 5G+. Standalone 5G uses a 5G core rather than leaning on 4G, which helps response times and reliability in busy places. O2 says 5G+ now reaches more than 86% of the UK population, the widest standalone network in the country, with recent switch ons in Kent, Northern Ireland, Bristol and Cumbria. O2 moved its customers to 5G+ in March 2026 at no extra cost, without the need for a premium plan. You need a phone that works with standalone 5G, as listed in our guide to which phones work on 5G+.

Wide 5G+ reach does not yet mean much 5G+ use. In Opensignal’s study for January to March 2026, O2 users were on 5G+ for 5.3% of the time, against 8.3% for EE users.

O2 in the 2026 tests

The pattern across the tests is clear. O2 users find a 5G signal more often than Vodafone or Three users, but speeds are slower once connected. The RootMetrics results suggest O2 is improving faster than its rivals in 2026. EE still leads most measures, as EE’s test results show, and you can see the full rankings from each test in one place.

Plans

O2 offers phone contracts, SIM only plans, data only and smartwatch plans, and two kinds of pay as you go. Pay monthly plans need you to pass a credit check for a phone contract, while pay as you go does not.

Plan types

Phone contracts and 12 or 24 month SIM only plans come as Classic, Plus or Ultimate. Each includes unlimited UK minutes and texts, 5G and the option to change your data allowance once a month in My O2. One month SIM only plans are called Mini plans and have fewer extras.

O2 Extras include Disney+, Amazon Prime, Audible and Cafeyn, depending on the offer at the time.

Phone contracts

O2 phone contracts use O2 Refresh, which splits your bill into two parts. The Device Plan is a credit agreement for the phone, where you choose the upfront payment and a term of up to 48 months. The Airtime Plan gives you your data, minutes and texts. The two are linked for the first 24 months and then unlink, so you can drop the airtime later and keep paying for the phone in instalments.

Switch Up, included with Plus and Ultimate phone plans, lets you swap your phone every 90 days for a new model or one of O2’s Like New refurbished phones. Our guides explain device plans and airtime plans, the rules on when you can upgrade, and the case for buying outright or on contract.

SIM only

SIM only plans come on 24 month, 12 month and 1 month terms, with data from 3GB to unlimited. These are sample prices from O2’s site.

Before you choose, work out the right data allowance for your use. Our guide to SIM only plans in general explains contract terms in more detail.

Pay as you go

O2 pay as you go has no contract and no credit check, and every plan can be taken on a physical SIM or an eSIM. There are two types. With Big Bundles, you top up and O2 swaps your credit for a monthly allowance, which renews if you have enough credit. Rolling plans take a card payment automatically each month and give more data for the same price. You can switch between the two once a month in My O2.

Both types include unlimited UK minutes and texts, 5G, data rollover, Europe Zone roaming up to 25GB and O2 Rewards, which pays back up to 10% of what you spend. The larger bundles also include some minutes to 42 countries.

Extra data offer for SIMs activated between 1 October 2026 and 31 March 2027. Prices checked on 29 October 2026. You can compare other contract free SIMs in our guide.

Essential Plan

The Essential Plan is O2’s social tariff for account holders receiving Universal Credit, the Guarantee Credit part of Pension Credit, Income Support, income based Jobseeker’s Allowance or income based Employment and Support Allowance. O2 checks eligibility with the Department for Work and Pensions.

Price rises

O2 raises pay monthly airtime by a fixed amount in pounds and pence each April. The amount is shown before you sign, and new contracts list the price for each year of the term.

In October 2025, O2 applied the higher yearly amount to customers already in contract, not only to new ones. Those customers had 30 days to leave without a penalty. Ofcom called the move disappointing but did not take action, and O2 complaints rose sharply in the months that followed. Our guide shows how other networks set their yearly rises.

Wi-Fi calling, 4G calling and eSIM

Wi-Fi Calling and 4G Calling are free on compatible phones, on both pay monthly and pay as you go. Pay as you go customers only gained both features during 2025, ahead of the 3G switch off. O2 also offers 5G Calling to pay monthly customers with a newer SIM and a compatible phone in supported areas, so calls can stay on 5G+ rather than dropping back to 4G.

Wi-Fi Calling helps in homes with weak indoor signal, but it does not work outside the UK. 4G and 5G Calling work abroad in selected countries.

You can choose an eSIM on pay monthly plans and on every pay as you go plan. O2 also offers smartwatch plans for cellular watches.

Roaming abroad

O2 is the only one of the four main networks that still includes roaming in Europe without a daily charge on standard plans. You can use your UK allowances in more than 40 Europe Zone destinations for holidays and short trips. If your UK data allowance is over 25GB, you can use up to 25GB of it in the Europe Zone each month.

Pay as you go roaming does not include Guernsey, Jersey, the Isle of Man, Monaco or Switzerland, which are inside the Europe Zone for pay monthly customers. Outside every zone and without a bolt on, standard roaming rates apply. See what the other networks charge abroad before you travel.

Extras and perks

• Priority: rewards, treats and 48 hour early access to tickets for gigs and events, for O2 pay monthly and pay as you go customers.
• O2 Extras: a streaming or app subscription for three months on Classic, six months on Plus and for the life of the plan on Ultimate.
• Volt: if you also have Virgin Media broadband, eligible O2 plans get double data and roaming in 75 destinations. Our page on Volt benefits for Virgin Media customers lists the broadband side of the offer.
• Multisave: 20% off the airtime of each extra line in a group of up to 20 numbers, useful when setting up a phone for a child. Ultimate plans are excluded.
• Warranty and insurance: Plus phone plans include a 3 year warranty against faults, and Ultimate phone plans include O2 Insure Ultimate Cover for loss, theft and damage. On other plans, you may want separate cover for your phone.
• O2 Rewards: pay as you go customers get up to 10% of their spending back as credit.

Customer service and switching

O2’s complaint record has been patchy. In Ofcom’s figures for July to September 2025, O2 was among the most complained about pay monthly mobile providers, mainly over how it handled complaints. In October to December 2025, after the price rise change, it was the most complained about provider, with seven complaints per 100,000 customers, more than double the industry average. By January to March 2026, this fell to three per 100,000, still just above the average of two.

You can get help through the My O2 app, live chat, the O2 Community forum or an O2 store. You can also call 202 from an O2 phone or 0344 809 0202 from any other phone.

Switching to or from O2

To join O2 and keep your number, text PAC to 65075 from your current phone and give the code to O2. To leave O2 and keep your number, text PAC to 65075, or text STAC to 75075 if you do not need the number. You can also request either code in My O2.

On an O2 Refresh phone plan, there is no early termination charge on the airtime. If you leave within the first 24 months, you must pay off the Device Plan in full. After 24 months, the plans unlink and you can keep paying for the phone in instalments. SIM only contracts do carry early termination charges if you leave during the minimum term. If you are in a Multisave group, leaving may change the discount for the other lines. Our guide to switching networks step by step goes through each stage.

You can line up O2 against deals on other networks, or read how O2 compares with the other three networks.

Frequently asked questions

Are O2 and Virgin Media the same company?

Yes. Both are brands of Virgin Media O2, which Liberty Global and Telefónica own equally. They still have separate plans and accounts, but having both unlocks Volt benefits.

Which other brands use the O2 network?

giffgaff and Tesco Mobile, which Virgin Media O2 owns or part owns, and Sky Mobile all use O2’s masts, so their coverage matches O2’s. Virgin Mobile stopped taking new customers in 2023 and its users moved to O2. Reports in October 2026 say Virgin Media O2 is considering bringing the brand back, but nothing is confirmed. Our guide lists the smaller brands on each big network.

Will my older phone still work on O2?

A phone that only uses 3G will not work, as O2’s 3G network is closed. A phone without 4G Calling can still make calls over 2G until O2 starts its 2G switch off in summer 2029.

Can O2 Satellite be used for normal calls?

Not yet. It carries data for selected apps, such as WhatsApp and maps, but not normal calls or standard texts. You also need to add the bolt on before you head into an area with no signal.

Can I leave O2 because of the higher yearly rise?

The penalty free window for the 2025 change has closed. For contracts taken since 23 October 2025, the rise is part of the contract, so it does not give a right to leave. If O2 changes the amount again during your contract, it must let you leave without a penalty.

Can I switch between Big Bundles and Rolling plans?

Yes, once a month in My O2, and you keep your number. If a Rolling plan card payment fails and you do not update your card, O2 moves you to the lowest priced Big Bundle.

Does Virgin Media O2 have a social tariff for broadband too?

Yes. Virgin Media offers Essential Broadband to people on the same benefits as the Essential Plan. You can compare broadband social tariffs from other providers as well.