Is it cheaper to get a SIM only or a phone contract?

It’s almost always much cheaper to get a SIM only deal instead of a mobile phone contract. This is because you’re only paying for your calls, texts and data, rather than paying off the cost of a handset. However, if you don’t have a mobile phone you’re happy with, getting a phone contract can help you spread the cost of a new device. Check out our best O2 mobile phone deals.

Are O2 SIM cards free?

O2 doesn’t charge for SIM cards, so you can send off for a pay as you go one or sign up for a contract without having to pay for the card. However, you will need to pay to use the SIM, whether that’s by signing up for a monthly contract, or choosing O2 pay as you go.

Do I have to top up my O2 SIM every month?

If you choose an O2 pay as you go SIM, you don’t need to top up every month. However, if you don’t top up or purchase a bolt-on at least once every six months, your mobile will be disconnected and you’ll end up losing any credit you had left. On O2, the minimum top-up requirement is £10.

Can I get a 5G enabled O2 SIM card?

Yes, all new O2 SIMs are now 5G enabled. However, you’ll need to use it in a 5G-compatible mobile phone and be in an area where 5G is up and running if you want to take advantage of these superfast speeds.

Our best O2 SIM only deals in June 2023

Author Catherine Hiley Last updated March 7th 2023

How do I choose the best O2 SIM only deal for me?

If you’re looking to switch networks, O2 is a fantastic choice. It delivers 97% 4G coverage across the UK to all its customers, along with 5G in a growing number of locations. On top of this, it’s one of the only major networks that still offers EU roaming for no extra charge. And it has a fantastic rewards app that comes with freebies, discounts and priority tickets for events at O2 venues.

And once you’ve decided on signing up for an O2 SIM, the next thing you need to work out is how much data you need. Most O2 SIM deals come with unlimited calls and texts, so the biggest decision you need to make is how much data you think you’ll need and how much you want to pay per month.

Generally speaking, an average smartphone user gets through roughly 3GB a month. This is typically enough to cover general use, like checking emails, sending WhatsApp messages and scrolling through social media.

However, a lot of this depends on how much time you spend connected to Wi-Fi, either at home or at work. So, if you’re on the move a lot, you might want to consider signing up for a larger data plan.

If you’d like to find out how much data you get through in a month, simply take a look at your network’s app. There, you’ll find a monthly breakdown of how much data you’re using.

Why choose an O2 SIM only deal?

Named Most Popular Network in 2022: O2 won our Uswitch award for the Most Popular Network in 2022 thanks to its excellent coverage, generous roaming policy and impressive perks and benefits.
Excellent coverage: O2 delivers fast 4G coverage to 97% of the UK. And it has a fast 5G network that spans a growing number of towns and cities around the country. So, you should be able to enjoy fast speeds from almost anywhere in the UK.
Inclusive EU roaming: O2 is one of the only networks in the country that has chosen not to reintroduce roaming charges for travel to EU countries after Brexit. This means that, if you’re on O2, you can continue to use your regular allowance of calls, texts and data for no extra cost while you’re in any EU country.
O2 Priority: O2 is famous for its O2 Priority app, which gives users the chance to buy tickets for events at O2 venues before they go on general sale. And, even better, the app has regular competitions, special offers and freebies for its customers to enjoy.

What SIM only deals does O2 offer?

O2 offers a wide range of SIM only deals, from cheap SIM plans to big, unlimited data contracts. At the time of writing, O2 SIM only plans start from just £6 a month for 4GB of data, all the way up to an unlimited data SIM for £28 a month.

At the time of writing, O2 currently offers SIMs to suit all needs, including:

Unlimited data
Pay as you go
5G SIM only deals
Cheap deals

O2 delivers 5G SIM only deals as standard now, with even its cheapest plans able to connect to 5G networks. However, you should bear in mind that your mobile phone also needs to be 5G-enabled for you to be able to take advantage of those faster speeds.

All of O2’s SIM only contract deals last for 12 months, so you’ll be tied in for a year. Unless, of course, you opt for an O2 pay as you go SIM, which means that you only pay for the usage you need. If you’re not planning on using your phone regularly, this might be a good option for you. But if you’re planning on using it for regular calls, texts and internet use, you’d probably be better off signing up for a cheap O2 SIM deal.

What length of contract is available on O2?

O2 SIM only deals usually last for 12 months. Alternatively, you could opt for an O2 pay as you go SIM, although these can work out more expensive if you use your phone regularly.

Want an O2 phone contract instead?

Take a look at our best pay monthly deals from O2 today.

Compare O2 mobile phone deals

Can I use my O2 SIM abroad?

Woman smiling and looking at mobile phone

Yes, you can use your O2 SIM abroad, although, depending on your destination, it might end up costing you more. O2 won our Uswitch award for Best Network for International Roaming in 2022 because it was the only major UK network that didn’t reintroduce international roaming charges in EU countries after Brexit.

This means that you can use your monthly allowance of minutes, messages and data without paying an extra charge while you’re in any EU country.

If you’re travelling further afield, such as to the US, Canada or Australia, you can buy a bolt-on for an extra £6 a day.

To find out more, check out our guide on international roaming on O2.

How do I activate my SIM?

O2 makes it really easy to activate its SIM cards. If you’ve received a physical SIM card, it should be ready to go. All you need to do is pop it into your handset and it should start working straight away. If it doesn’t, you may need to restart your device.

If you’ve got an eSIM, you’ll need to download the eSIM profile onto your device. To do this, just scan the QR code included in your eSIM pack.

Can I keep my number with an O2 SIM only deal?

Yes, it’s easy to keep your number if you’re switching to an O2 SIM only deal. All you need to do is text PAC to 65075 and you’ll receive your PAC. Then, all you need to do is contact O2 and give them the code, so they can transfer your new number for you.

You can call O2 on 034 4809 0222.

Check out our step by step guides to transferring your number over from different networks:

From iD Mobile to O2

From Asda Mobile to O2

From Lyca Mobile to O2

From Talkmobile to O2

From Sky Mobile to O2

From SMARTY to O2

From Tesco Mobile to O2

From VOXI to O2

From Three Mobile to O2

From Vodafone to O2

From Virgin Mobile to O2

From giffgaff to O2

From Lebara Mobile to O2

What happens at the end of an O2 SIM only contract?

You’ll receive an email or text message from O2 once you’re nearing the end of your contract. Once you’ve received this, you’ll be able to go onto your O2 app and find upgrade options. However, these aren’t generally the most competitive deals and you should be able to find options that are much better value for money if you shop around. If you want to check out some options, compare our best SIM only deals on Uswitch.

Other networks

O2 not right for you? There are many UK networks with a range of products available. No matter your budget, data requirements, or handset preference, you’ll be able to find the ideal package: