O2 SIM only deals

Compare O2 SIM-only deals

O2 offers a wide range of SIM-only plans with different data allowances, all including unlimited UK calls and texts.

You can choose between 30-day, 12-month and 24-month plans, depending on how much flexibility you want. Prices vary depending on data allowance and contract length, with longer plans often offering better value.

Our best O2 SIMs this week

Compare O2 SIM-only deals

O2 offers a wide range of SIM-only plans with different data allowances, all including unlimited UK calls and texts.

You can choose between 30-day, 12-month and 24-month plans, depending on how much flexibility you want. Prices vary depending on data allowance and contract length, with longer plans often offering better value.

Why choose an O2 SIM?

• Excellent coverage: O2’s network covers around 99% of the UK population for 4G
• Flexible plans: Choice of 30-day, 12-month and 24-month contracts
• 5G included: Available at no extra cost on compatible devices and in supported areas
• O2 Priority: Access to exclusive rewards, offers and presale tickets
• EU roaming: Included on many plans, subject to a fair usage limit (typically up to 25GB)
• Extras: Some plans include perks like subscriptions or additional benefits

Read our full O2 review for more info.

O2 rewards and O2 Priority: what do you get?

O2 Priority is one of the network’s key features, offering access to a range of rewards and experiences.

This includes early access to tickets for events at O2 venues, as well as regular offers and discounts across food, retail and entertainment brands. Customers may also receive perks such as venue benefits or limited-time rewards through the app.

Is O2 a good network?

O2 is generally considered a reliable network with strong coverage across the UK. As a core network provider, it offers broad availability and stable performance in most areas.

While speeds can vary depending on location, O2 focuses on consistency and added value through perks and customer benefits. It may not always be the fastest network, but it offers a good balance of coverage, reliability and extras.

What to look for in an O2 SIM

When choosing an O2 SIM, the main factors to consider are your data allowance, contract length and any included perks.

All plans include unlimited UK calls and texts, so your decision will largely come down to how much data you need and whether you want additional benefits like roaming or entertainment extras.

O2’s best unlimited data SIMs

O2 offers unlimited data plans across 30-day, 12-month and 24-month contracts, making them suitable for heavy users who stream, browse or use their phone as a hotspot.

These plans include unlimited UK calls and texts, along with 5G access where available. As with all networks, usage is subject to fair use policies.

O2’s best rolling contract SIMs (30-day / 1-month)

O2 offers 30-day rolling SIM-only plans, giving you the flexibility to change or cancel your plan each month.

These plans include unlimited UK calls and texts and a range of data allowances. However, some perks—such as inclusive EU roaming—may not be available on all 30-day plans, so it’s worth checking the details.

O2’s best 12-month SIM deals

O2’s 12-month SIM-only plans offer a balance between flexibility and value.

They typically include unlimited UK calls and texts, a choice of data allowances, and access to features like O2 Priority and inclusive EU roaming (subject to fair usage limits).

O2’s cheapest SIM-only deals

O2’s cheapest SIM-only deals are aimed at light users who mainly need calls, texts and a small amount of data.

While O2 isn’t always the lowest-cost provider, entry-level plans are competitively priced and include access to O2’s network and core features.

Does O2 offer SIM plans for bad credit?

O2 typically carries out a credit check for pay monthly SIM-only plans. If you have bad credit, acceptance may be more difficult.

In some cases, alternative options such as deposits or different plan types may be available, depending on your circumstances.

O2 SIMs with unlimited data

O2 offers unlimited data plans across multiple contract lengths. These are designed for heavy users who don’t want to worry about data limits.

As with all networks, usage is subject to fair use policies, particularly for activities like excessive tethering or non-personal use. Check out O2's terms and conditions for more details.

Alternatives to O2

If you’re comparing networks, alternatives like Vodafone, EE and Three also offer full network coverage, while providers such as giffgaff, Tesco Mobile and Sky Mobile use O2’s network.

Each network offers different pricing, features and perks, so it’s worth comparing deals to find the best option.

Can I use my O2 SIM abroad?

Yes, O2 allows you to use your allowance in its Europe Zone on many plans, subject to a fair usage limit (typically up to 25GB). Roaming beyond Europe may require a daily charge or add-on, depending on your plan.

Can I get 5G enabled O2 SIMs?

Yes, all O2 SIMs are 5G-ready. You’ll need a compatible device and to be in an area with 5G coverage to access it.

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

Yes, you can keep your number by requesting a PAC (port authorisation code) from your current provider and giving it to O2.

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

Yes, your phone needs to be unlocked to use an O2 SIM. Most phones sold in recent years are already unlocked.

Are O2 SIM-only deals cheaper than contract?

SIM-only deals are often cheaper overall because you’re not paying for a handset. However, phone contracts can spread the cost of a device over time, which may suit some budgets.