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O2 Review
O2 is one of the UK's most established and popular mobile networks, known for striking a strong balance between performance, value, and customer perks...
Network Info
4.0/5
Major Network
5G Ready
Pros & Cons
Pros
- Only major UK network offering free EU roaming with up to 25GB data on eligible plans
- Excellent Priority rewards programme with early access to event tickets, weekly deals, and venue perks
- Strong 5G Standalone rollout covering over 500 towns and cities
- Good balance of price and performance, sitting between budget networks and premium-priced EE
Cons
- Slower median 5G speeds compared to EE and Three, ranking last among the big four for raw 5G performance
- Free EU roaming only available on 12-month and 24-month plans, not on rolling monthly contracts
- Customer service can be inconsistent, with mixed reviews for complaint resolution
Overview
O2 is one of the UK's most established and popular mobile networks, known for striking a strong balance between performance, value, and customer perks. Originally launched as BT Cellnet before rebranding to O2 in 2002, the network was acquired by Telefonica in 2006 and has since become a cornerstone of the UK mobile market. In 2021, O2 merged with Virgin Media to form Virgin Media O2, creating one of the UK's largest telecommunications companies.
With over 34 million customers, O2 is one of the biggest networks in the UK by subscriber count. The network has invested heavily in its infrastructure through a 700 million pound Mobile Transformation Plan, expanding both 4G and 5G coverage while targeting persistent problem areas along motorways, railways, airports, and stadiums. O2's 5G Standalone network now reaches over 500 towns and cities, covering more than 70% of the UK population.
O2 distinguishes itself from competitors through its highly regarded Priority rewards programme, which offers customers access to exclusive event tickets, weekly deals, and venue perks at no extra cost. The network is also the only major UK operator to offer free EU roaming on eligible plans, making it a particularly attractive choice for frequent travellers to Europe.
Coverage & Speed
O2 offers solid nationwide coverage with 4G reaching 99% of the population and an expanding 5G Standalone network in over 500 locations. While 5G speeds are slower than some competitors, the breadth of 5G coverage is among the best in the UK, and O2 does not impose speed caps on any of its plans.
Plans & Pricing
O2 offers a straightforward range of pay monthly phone contracts, SIM-only deals, and pay-as-you-go options. All Pay Monthly plans include 5G access, and the network's plans are generally priced competitively between budget operators and premium EE.
Roaming
O2 stands out as the only major UK network to offer free EU roaming on eligible plans. Customers on 12-month and 24-month contracts can use their UK data, calls, and texts in 47 European countries at no extra cost, with a fair usage cap of 25GB for data. Rolling monthly contracts do not include free roaming. Beyond Europe, O2 charges for roaming in other destinations with optional travel bolt-ons available. The 25GB roaming cap means heavy data users may need to supplement with local SIM cards or WiFi abroad.
Our Verdict
O2 occupies a strong middle ground in the UK mobile market, offering a compelling combination of solid network performance, genuine customer perks, and the standout benefit of free EU roaming. The Priority rewards programme is arguably the best loyalty scheme in UK mobile, providing real, tangible value through event access, weekly deals, and venue benefits that go well beyond token gestures.
The network's main weakness is raw speed. O2's 5G network, while extensive in geographic coverage, delivers slower median speeds than EE and Three, which may matter to users who demand peak performance. Customer service also receives mixed reviews, with some users finding complaint resolution frustrating. The 25GB roaming cap, while generous, can catch out heavy data users abroad.
For the average UK mobile user who travels to Europe regularly, enjoys live events, and wants a network that rewards loyalty without charging premium prices, O2 is an excellent choice. The combination of free EU roaming and Priority perks creates a value proposition that no other major network matches. Those who prioritise raw network speed above all else may prefer EE, but O2 delivers where it counts for most people.