Looking at joining O2 Mobile?
In this article, we’ve reviewed O2, based on our experiences using one of their SIM-only plans.
We’ve assessed this mobile network based on their speeds and coverage, customer service, value for money, and more, to see if you should join the O2 network.
Before we begin, if you’re searching for a new mobile plan, on O2 or any other network, use our comparison site to find the cheapest pay monthly phone plans or SIM-only deals on the market right now.
Contents
- O2 overview
- Coverage and speeds
- Roaming allowances
- Value for money
- Customer service
- Verdict: should you join O2 Mobile?
- Alternatives
- Conclusion
O2 overview
O2 is one of the big four mobile networks in the UK, meaning they have their own 4G and 5G masts, rather than reselling access through another network.
They offer a range of pay monthly phone and SIM-only deals, as well as tablets and mobile broadband devices.
Most O2 SIM plans are available on a long-term contract, and you can also choose a month to month pay as you go agreement as well.
Compared to the other big four networks, O2’s range of pay as you go SIMs is quite good, although there isn’t an unlimited data plan on offer at the moment.
On their tariffs with a long-term commitment, O2 often includes certain extras you can choose between when you sign up, such as free Amazon Prime or Disney+ access.
There are also special benefits on offer for existing Virgin Media broadband customers. When you buy an O2 Mobile contract, you can normally get a free speed boost on your broadband plan, which is nice.
Unlimited calls and texts to UK numbers are included as standard on all O2 Mobile plans, as well as WiFi calling.
O2 also offers eSIM compatibility when you buy a new handset from them. If you’re just buying a SIM though, getting an eSIM can be a bit tricky – they don’t currently offer eSIMs on their pay as you go plans at all.
Coverage and speeds
When it comes to 4G coverage and speeds, O2 performs very well.
We generally saw strong speeds when testing on 4G LTE, and good coverage as well.
Calling performance was also good, with no dropouts or call quality issues, testing in suburban and certain remote locations in the West Midlands.
However, O2 isn’t the best when it comes to 5G speeds.
We personally saw download speeds of 200-250 Mbps over 5G with O2, which is great. But according to data from Ookla, they have the slowest median 5G speeds of any of the big four networks.
Three is the fastest, followed by Vodafone, then EE, then O2.
There is an upside to O2 from a 5G point of view though: they don’t put speed caps on their plans.
This is why, with an O2 pay as you go SIM, we were still able to get speeds of 200 Mbps or more on 5G. Most Vodafone and EE SIMs for example are limited to 100 Mbps.
So, if you want to prioritise 5G speeds, whether O2 is any good or not depends on what type of SIM plan you need.
If you want a cheap pay as you go SIM, O2 is a good choice if you want to join one of the major networks, given that they have no speed caps (although Three 5G is also unrestricted).
But if you’re looking for a pay monthly phone plan, or a more expensive long-term SIM, you’ll likely get uncapped speeds with any of the other major networks – and their average 5G speeds will be higher, in most parts of the country.
It’s also worth mentioning, in terms of 5G coverage, we think O2 performs fairly well. We were able to get speeds of 100 Mbps or more on a very consistent basis.
Roaming allowances
O2 is the best big four network when it comes to roaming.
Currently, they let you use 25GB of your monthly allowance in 45 different European countries, free of charge, whether you’re on a pay monthly or pay as you go plan.
This might not seem like much if you have a 100GB+ data limit, but it’s a lot higher than what most other networks offer. The limit is just 12GB with Three, for example.
Outside of Europe, you can buy an O2 Travel Bolt On, to save money when roaming in countries like Australia, New Zealand, and the USA.
It gives you unlimited calls, texts, and data, for a pretty low monthly cost.
O2 is a great choice if you often travel abroad. And if roaming is important to you, you might also like to consider Tesco Mobile.
This is a mobile virtual network operator (MVNO) that piggybacks off the O2 network, but offers unlimited roaming in the EU at the moment (up to your plan limit).
The downside to Tesco compared to O2 is, they don’t have an add-on you can use to minimise your roaming costs outside of Europe. Instead, you’ll need to pay per megabyte of data used.
Value for money
O2 can offer good value for money, but some networks, particularly smaller ones, often offer better deals.
O2’s plans are fairly price-competitive with Vodafone and EE, especially given that these other networks often have speed limits, unless you pay more for an unrestricted tariff.
However, Three is often cheaper, even though they offer faster average 5G speeds, and have no speed caps at all.
And if you’re willing to look at MVNOs, iD Mobile, which piggybacks off Three, can offer even lower prices on pay monthly SIMs.
It’s a similar story on pay as you go plans. O2 isn’t the cheapest, given the amount of data they include, especially compared to smaller providers, like Smarty.
And if you want to use a big four network, Three tends to offer cheaper pay as you go SIMs.
On pay monthly phones, O2 can offer good value for money, especially if you can take advantage of some of the freebies and extras they include.
However, in general, we’ve found networks like Three often have lower prices on the same phones with similar data limits.
To see if O2 offers good value on a phone you’re looking at, compare pay monthly handsets on our comparison website.
Customer service
We had a good experience with O2 customer service, but the data suggests that other customers have had issues in this area.
They have a phone number you can call, unlike some other cheaper networks, and we found their team was quick to answer the phone.
O2 support was quite helpful with a billing query we had, and they were knowledgable when we asked about eSIMs, informing us that we couldn’t use one as we were on a pay as you go contract.
However, according to Ofcom data, O2 is the most complained-about major mobile network in the UK at the moment.
As of the most recent Ofcom report, they received five complaints per hundred thousand customers on average, compared to two with EE, Vodafone, and iD Mobile, and just one with Tesco and Sky Mobile.
This number is not extremely high, but it is more than double the number of complaints that most other mobile networks are receiving right now.
If you want better customer service, EE, Tesco Mobile, or Vodafone may be a better choice than O2 at the moment.
Verdict: should you join O2 Mobile?
From our testing, O2 performs well, and we had a good experience with them.
Our 4G and 5G speeds were strong, and we had no issues with coverage in suburban and slightly rural areas.
We also found that their customer service performed well when faced with basic queries, and were quick to answer the phone.
However, according to the data, some customers have had issues with O2’s customer service, enough to result in a fair number of complaints to Ofcom.
And while O2’s range of pay monthly phone and SIM deals is good, they’re not always the cheapest on the market.
Also, statistically, O2 has the slowest 5G network of any of the big four carriers in the UK.
Overall, we rate O2 3.7 out of 5. They can be a great choice if you want a pay monthly SIM or phone plan, and their pay as you go offers aren’t bad either – especially if you want a high roaming allowance. However, it would be good if they offered faster 5G speeds, and slightly lower prices.
Best O2 alternatives
If you’re not set on using O2, here are some other mobile networks you might also like to consider.
1. Three
Three has the fastest 5G network in the UK, and they normally also offer great value for money, even on pay as you go SIMs.
Their customer service also performs better than O2, on average, which is good.
The downside to Three is, their roaming allowances are nowhere near as generous as what O2 offers at the moment.
2. 1pMobile
The EE network currently offers better 4G coverage and faster average 5G speeds compared to O2 – but buying an EE SIM can be very expensive.
1pMobile piggybacks off EE, and they offer a range of flexible month to month SIM plans, allowing you to access the EE network for a much lower price.
It’s worth knowing though, this is a fairly basic provider, with no pay monthly phone contracts, or benefits/extras other than roaming on their plans.
3. Tesco Mobile
Tesco Mobile uses the O2 network, but offers better customer service, and stronger roaming allowances.
As we touched on earlier in the article, you can use your entire data allowance overseas in the EU as a Tesco Mobile customer.
Plus, they support eSIMs as standard, and offer discounts if you’re a Tesco Clubcard member.
Conclusion
This is the end of our O2 Mobile review.
If you’re still not sure which network to join, leave us a comment below, and we’ll get back to you as soon as we can.
About the author
Tom is the founder of Green Smartphones. You’ll find him writing about phones on the Green Smartphones blog, or talking about SIM deals and mobile networks on our YouTube channel. He’s the Android expert on the team – currently using a Google Pixel 9, recently upgrading from a very long-suffering Note 20 Ultra. When he’s not working on Green Smartphones, you’ll find him playing football or hiking.