Compare the best SIM-only deals

There's no need to take out a contract on a new phone if you're already got one you like - all you need is a SIM-only plan. And luckily you have plenty of choice. Here's everything you need to know to find a pay-monthly SIM-only deal that works for you - by comparing what you can get with CompareMyMobile.

Compare SIM deals

How to find the best SIM-only deal

Use our mobile comparison tool to help you find the best SIM-only deal. We'll let you see dozens of SIM deals from UK mobile networks all in one place, ranked by price, so you can spot the best ones at a glance.

Compare SIM-only deals

The very best SIM deal of all, of course, is the one that gives you everything you want from a plan at the lowest possible cost. Adjust the filters at the side of the comparison table to just show the sort of deals you want, then sort them by cost with the selector at the top.

Here are a few things to think about when navigating the table and choosing a deal…


There's a huge spread on offer here - you can get pretty much any allowance you like. SIM tariffs range from the tiny (100MB data, plus a few hundred minutes and texts) to the huge (unlimited everything). See this guide for more info on working out how much allowance you need.


You have plenty of networks to choose from for SIM deals too. Some are nice and cheap, others are packed with benefits, and you may even be able to snag a special deal from your current mobile network or broadband / TV provider. Either way, make sure you check coverage in your area before you commit to a deal.

Contract length

Long-term SIM deals are usually cheaper over the year than one-month ones - while short-term deals have the advantage of letting you chop and change your plan whenever you want.

Best 30-day SIM-only deals

Prefer a one-month SIM deal that you can alter or cancel whenever you like? You've got a lot of choice. Networks that offer 30-day deals on SIMs include…

It's particularly easy to change your allowance on networks that are technically PAYG, such as Asda Mobile, giffgaff, and Lebara Mobile - take a look at those if you really value flexibility.

Bear in mind that some networks dial back the benefits for one-month plans, so you may not get access to all the same stuff you would on a long-term contract. That's not universal, though - many still let you use things like tethering, extended roaming, and perks like O2 Priority.

Learn more about how to find the best 30-day SIM deal here.

Compare 30-day SIM deals

Best cheap SIM-only deals

Find the cheapest SIM-only deals by sorting our comparison table by cost. Use the toggle in the top right, and all the lowest-priced SIMs will float to the top. You can also set a maximum price that you'd be willing to pay each month in the sidebar filters, and take a look at everything available in your budget.

For cheap SIM plans, try small networks that specialise in low prices, such as:

Compare cheap SIM-only deals

Best SIM-only deals for iPhone

SIM cards from all networks will work in iPhones, as long as you get the right size:

  • iPhone 5 or newer - nano SIM
  • iPhone 4 or 4S - micro SIM
  • Original iPhone, 3, or 3G - standard SIM

As for allowance, newer iPhone models and Plus versions will probably need a little more data than average, especially if you're upgrading. It means you'll probably use your phone more, and web pages will load quicker, resulting in more data usage - and viewing video on such a big screen requires a bit more data too.

Some networks even have bonus extras that you can make use of. Vodafone and Three, for instance, have options for streaming video more cheaply.

Best SIM-only deals for Samsung Galaxy

As with iPhones, you'll need a decent data allowance for a Samsung Galaxy phone. It'll let you use all your apps, and there's enough data to handle fast processing speeds, high-res video streaming, and uploading quality photos to social media.

Again, you can get a SIM for your Samsung from any network, provided you select the right size SIM card:

  • Samsung Galaxy S6 or newer - nano SIM
  • Samsung Galaxy S5, S4, S3 - micro SIM
  • Samsung Galaxy Note 5, 7, or 8 - nano SIM
  • Samsung Galaxy A (including A3 and A5) - nano SIM

Can I keep my phone number if I switch network?

Yes, you can keep your current mobile number if you switch to a SIM on a different network. In fact, it's easy - there's no reason at all to stick with the same network if you can get a better SIM deal elsewhere.

To get a new deal and keep your number, simply sign up to the deal, then contact your current network for a PAC (porting authorisation code) number. Once your new SIM arrives and you've activated it, contact your new network and give them the PAC. Just make sure you do so within 30 days of receiving the code, or it'll expire.

Once the porting is underway, your phone number should transfer over to your new SIM card within a few days.

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