O2 SIM only deals

Our best O2 SIMs this week

Why choose an O2 SIM? 

• Good coverage: O2’s coverage is excellent for 3G and 4G, covering 99% of the UK population. Its 5G network is also widely available
• O2 Rewards offers and O2 Priority: O2's exclusive customer rewards scheme is one of the best around. You can get deals from high street brands, weekly treats, and priority ticket-booking to gigs at O2 venues
• Roaming: O2 still offers inclusive EU roaming with its 12-month and 24-month SIM plans, meaning you can use their texts, calls and data allowance (up to 25GB) for no extra cost in any location that’s part of O2’s ‘Europe Zone’. For international roaming, there’s the O2 Travel Bolt On, which gives you unlimited texts, minutes and data (included with select plans, or available as an add-on for a fixed daily rate) in 27 destinations outside Europe
• Customer service: All calls made to O2’s customer service helpline are free when made from a pay monthly handset
• Data rollover: O2 SIM-only customers can roll over any unused data at the end of the month
• Free Wi-Fi: O2 offers free access to Wi-Fi hotspots in more than 15,000 locations across the UK. Customers can also make calls over Wi-Fi
• Extra perks with SIM-only plans – Many SIM plans come with a free trial subscription to services like Apple Music, Prime Video, Disney+, among others. Plus, if you’re also a Virgin Media broadband customer, you can get double data on your O2 SIM plan and a broadband speed boost

O2 Rewards and O2 Priority: what do you get? 

O2’s exclusive rewards scheme is one of its biggest draws. As well as tempting deals and discounts from high street shops and restaurants, customers have access to:

• O2 Priority presale tickets – If you enjoy live entertainment, you’ll be pleased to hear that O2 customers can buy tickets for events at any O2 venue 48 hours before they go on general sale
• Perks at O2 venues and Twickenham – You’ll be able to enjoy plenty of perks at O2 venues and Twickenham, such as priority queuing, lounge access, free cloakrooms, and food and drink deals
• O2 Rewards – Pay as you go customers get up to 10% back every three months. You can use this as extra airtime credit with your plan, or put it towards money off other rewards

Is O2 a good network?

As Britain’s oldest and largest network, O2 is also one of the most popular – and for good reason. As well as plenty of choice when it comes to SIM-only plans, it offers pay-monthly contracts for many mid-tier to premium handsets and great perks.

Coverage is very good. Its 4G network reaches 99% of the UK population, and it has the best coverage for indoor and outdoor phone calls. Not to mention, O2 has one of the biggest 5G networks in the country, and coverage is widely available.

O2’s customer service is decent, with O2 scoring in line with the average rating in Ofcom’s 2022 report on mobile networks’ customer service. Even better, O2’s customer rewards scheme is arguably the best on the market, offering plenty of exclusive extras and perks.

All this means that O2’s plans can be a little pricier than other providers. If you’re on a budget, check out our cheap SIM-only deals.

Read our full O2 review for more info.

What to look for in an O2 SIM contract

When picking a SIM deal from any network, you’ll typically compare things like monthly data allowances, contract length and price.

With an O2 SIM contract, it’s also worth keeping an eye out for any extras on offer. Some plans come with free trial subscriptions to streaming services, or extra data. It’s also important to weigh up the monthly price versus contract length – for example, the 24-month plans are much cheaper than the 30-day ones, but you’ll be tied to a long contract.

As well as an extensive range of great SIM-only deals, O2 offers a handful of data-only SIMs for tablets or mobile broadband devices.

Cheap O2 SIM-only deals

Does O2 offer SIM plans for bad credit?

O2 will run a credit check on you before you sign up to any of its Pay Monthly SIM-only plans. If you’ve got bad credit, it will be more difficult for you to be accepted for an O2 SIM contract.

However, O2 do offer security deposit options if certain criteria are met.

12-month O2 SIMs

There are many options for 12-month contracts with O2, and these tend to work out cheaper than 30-day contracts. O2 also offers 24-month contracts, and the monthly cost for these is even lower.

Make sure you definitely want to commit to a long-term contract, though, or you’ll have to pay a cancellation fee. Nevertheless, we'd strongly recommend getting a 12-month or 24-month SIM contract over a 30-day plan. As well as a lower monthly outlay, EU roaming is only included with O2's 12-month and 24-month SIM plans.

O2 SIMs with unlimited data

O2 offers unlimited data on a 30-day, 12-month or 24-month plan. This means you can stream movies, listen to music and play games without worrying about going over your data limit.

Though the data is unlimited, that doesn’t mean you can do whatever you want. As set out in O2's terms and conditions, there are some limitations. This says O2 will monitor your usage, and if “you regularly tether to 12 or more devices, have used 650GB of data twice within a 6 month period, or have connected to a device other than an eligible device…then we may investigate your usage further to ascertain whether your Unlimited Data usage is for the permitted use.”

All that said, it’s very rare that you’ll go over these limits.

Should I get unlimited calls and texts?

All O2 SIM-only deals come with unlimited calls and texts.

Only one plan – that’s the 1GB 30-day deal – comes with 1,000 minutes and unlimited texts.

Can I use an O2 SIM card in card in any phone?

You can, as long as the handset isn’t locked to another network. If your new phone takes a different-sized SIM, you can request the correct size from O2 either online or in store.

If you’re wondering how to check if your phone is unlocked, read our guide.

Which networks offer good SIM plan alternatives?

Plenty of networks offer SIM-only deals, including:

• Three
• EE
• Vodafone
• Giffgaff
• Asda Mobile
• Virgin Mobile
• Talkmobile
• Sky Mobile
• iD Mobile
• VOXI
• SMARTY
• Lebara
• Lycamobile

Can I use my O2 SIM abroad?

Yes, O2 Roaming allows you to use your O2 SIM abroad. Depending on where you’re travelling to, roaming may be included in your SIM plan, or available as an add-on:

• EU roaming – O2 customers can use their normal allowance of texts, calls and data for no extra charge in any location that’s listed in O2’s Europe Zone
• International roaming – Travelling beyond Europe? There’s the O2 Travel Bolt On, which gives you unlimited calls, texts and data for a fixed daily charge. Some select O2 SIM-only tariffs come with the O2 Travel Inclusive Zone Bolt On, so you won’t have to pay anything extra

Do note, though, that inclusive EU roaming isn't available with 30-day SIM tariffs – only O2's 12-month and 24-month contracts.

For more on using your phone abroad, visit our page on roaming rules.

Can I get 5G enabled O2 SIMs?

Yes, all O2 SIM deals are 5G ready. Not to mention, O2 is among the best providers of 5G in the UK. However, be aware you'll need a 5G-compatible phone, too.

Can I keep my mobile number if I switch to an O2 SIM-only deal?

Yes, you can keep your old mobile phone number. If you’re moving from another network, you’ll need to get in touch with them to request your PAC (porting authorisation code). You will need to provide this to O2, who will then move your number over. Read our guide on keep your current mobile phone number for more information.

If you’re an existing O2 customer, you’ll need to fill in a ‘keep my number’ form on their website.

Do I need an unlocked phone to use an O2 SIM?

If your phone is from another provider, it may be locked to that network and therefore an O2 SIM would not work.

It’s easy to check whether your phone is locked by popping a friend or family’s SIM card (from a different provider to yours) into your phone.

If it works, then you’re good to go. Otherwise, you’ll need to contact your current operator and ask them to unlock it. Our page on how to check if your phone is unlocked goes into more detail.

Are O2 SIM-only deals cheaper than contract?

It's almost always cheaper in the long run to buy a phone outright and get a cheap SIM-only deal. However, because of the way O2's 'Refresh' contracts work, they're actually not that much more expensive than going SIM-only.

An O2 Refresh plan splits your monthly bill into two parts: the Device Plan, which is the cost of your device, and the Airtime Plan, which is the cost of your SIM with minutes, texts and data. This way, you can see that the only extra cost you pay on the handset is interest.