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The essential guide to SIM-only phone plans

By Hannah Ricci
Saturday, May 19th 2018

If you covet the freedom of a flexible, generous and affordable mobile phone plan without a binding phone contract, a SIM-only plan is ideal.

SIM-only tariffs have come a long way since the pay-as-you-go plans of old and now offer big savings over new phone contracts, with a wide variety of call, text and data bundles. Read on for all you need to know about these flexible friends.

How to choose a SIM-only deal

When deciding on which SIM-only deal to buy, you will need to take into account the amount of minutes, texts and data allowance you need. SIM-only plans often come with a choice of 30-day or 12-month contracts and you’ll notice that the shorter contracts cost a few pounds more each month.

If you don’t want to pay monthly by direct debit (which will continue to run until you cancel), you can choose a pay-as-you-go plan instead, when you actively top up with credit or buy a bundle of texts, calls or data only when you need to. Plus you won’t be tied to a contract.

SIM-only prices start from as little as £5

If you simply want to know what the best deals currently are, just check out our SIM-only comparison. SIMs are issued free of charge (providing you pre-load them with credit or take out a new plan) and packages start from around £5.

Compare SIM-only deals →

Check your mobile coverage

All UK mobile providers offer SIM-only mobile deals so it’s a case of checking which provider offers the best coverage in your area and choosing a plan that suits your usage pattern. The bonus of the 30-day contracts means you can always cancel without penalty if you don’t like it, and try a different package or a new network.

To check the coverage provided by any particular network, just click on any of the buttons below. You’ll be told instantly if you can get a connection there, how strong it’s likely to be and whether you’ll be able to get online.

Which size SIM to choose

There are four different SIMs on the market – mini SIM, micro SIM, nano SIM and combi SIM. They all perform the same job, but they're a different size (or changeable between mini micro in the case of the combi SIM) and so you need to pick the one compatible for your phone or tablet.

combi SIM is most common

Most providers supply the combi SIM, which gives you the best of both worlds. It's a standard SIM which has a micro SIM inside it. You can pop out the micro SIM for new smartphones, like iPhone 6 and Samsung S6, but you can also clip the micro SIM back in the frame to use for older phones.

Compare SIM-only deals →

The difference between 3G and 4G

Mobile broadband networks run on 3G and 4G, ideal for internet users on the go. 3G is the most widely available mobile technology, although 4G is now rapidly catching up. 4G – the fourth generation of mobile technology – is up to five times faster than 3G, leading to quicker downloads and a better online experience.

You may need to unlock your handset

If you’ve reached the end of a contract, your handset is likely to be locked to the initial provider and will need to be unlocked to be compatible with a new SIM from a different network. Phone unlocking is an entirely legal process in the UK, so don’t be afraid to consider it if you’ve previously been wary.

Unlocking a handset could could cost up to £20

Some phones can be unlocked for free by simply entering a special code from your network provider, while others may need to be unlocked by an expert at a cost of up to £20.

Unlocking your phone is usually safe, providing you use the code method rather than connecting to a third party device or software. Unlocking is undertaken at your own risk and may invalidate your phone’s warranty.


SIM-only is a smart option for anyone looking for an affordable, flexible option to call, text and get online. From the very lightest users to data-hungry customers keen on movies and games, there’s a plan to suit your needs.

SIM-only has shaken off its reputation as a basic, budget phone solution (although it offers this too), to provide great value bundles on flexible terms for those of us that don’t want to shell out on a new phone every two years.

Compare SIM-only deals →

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