Unlimited data SIM deals

The cost of unlimited data SIM plans can vary depending on the type of deal you choose. For example, an offer that includes roaming outside of the EU tends to be more expensive.

You might also find price differences between a SIM-only deal for your existing phone and what it might cost as part of a monthly contract with a new phone.

To work out if it could be good value for you, start by looking at past bills to see how often you’ve paid to top up your data. Add it all up and then compare it to the cost of a new unlimited data plan.

Under Ofcom rules, telecoms providers must make their pricing and any potential rises transparent at the point of sale.

How long do you want to be tied into a contract for? Is a flexible, rolling monthly plan important to you? If not, and you’re happy to lock yourself into a longer-term unlimited data plan, you might get a better deal.

We compare a range of SIM-only unlimited data phone deals, as well as monthly plans if you want a new phone. Each offers a selection of contract lengths to suit your needs:

• One month – these give you the most flexibility, allowing you to end your deal and swap to another after just a month. If you’re happy where you are, the contract simply rolls on. Because of this flexibility, you’ll tend to pay more than for longer fixed contracts.

• 12 months – less flexible than a rolling monthly plan. However, year-long contracts often reward you with a cheaper deal for locking yourself in.

• 24 months – similar to a 12-month deal, you can be rewarded with a lower price for signing up for a longer period. But if a better offer comes along, you won’t be able to switch without paying a fee to cancel your contract early.

You can usually make as many calls as you like and send any number of texts with an unlimited data plan. If you’re weighing up a plan with limits versus one with unlimited data, make sure that you have enough texts and call minutes to suit your lifestyle.

If you’re not sure how much you might need, check two or three of your previous bills to help you get an idea.

If you enjoy spending a lot of time on social media, consider a limited data deal with a twist – it includes ‘unlimited social data’ that doesn‘t count towards your other data allowance.

Slightly cheaper than general ‘unlimited data’ plans, they let you use your monthly data allowance elsewhere online.

There aren’t as many deals to choose from, and some may cover only one or two social media apps. But it means you can scroll, swipe, snap, post or chat to your heart’s content, and not worry that you’ll run out of data or face extra charges.

Some deals will throw in a freebie to entice you, for example, a three-month subscription to a streaming service such as Prime Video or Disney+. However, try not to be tempted if the plan isn’t really right for you. Think of any extras as a bonus if you were going to pick that plan regardless.

The big four networks (EE, O2, Three and Vodafone) have almost nationwide coverage. Some of the smaller providers rent space from these networks so they can provide services all over the country. Use a network coverage checker to see the coverage where you live, work and make regular visits.

It’s also worth checking which networks have local indoor and outdoor coverage. This is particularly important if you live in a remote location.

Try the Ofcom coverage checker. You can also use it to see if 5G is available in your area.

If you’re planning on using your phone abroad, check what, if any, roaming charges apply to your unlimited data contract.

Some providers offer data use overseas as part of their unlimited contract deals. However, others may restrict it, so always check the plan details before you sign up.