Compare SIM Only Deals

Find the best SIM only deals with our sim only comparison tool

SIM only plans are ideal for customers who are happy with their current handset and just want a great deal on bundled calls, texts and data. The comparison engine compares sim only deals on Multi SIMs; they are three in one SIM cards which break down from standard sim, to mini sim and then to nano sim for use in every type of smartphone or tablet.

If you're wondering what a SIM-only deal is then you are ordering a mobile phone SIM card without a handset. You then pay a monthly fee to get a set number of texts, minutes and data. To choose your ideal SIM only deal just browse the sim offers available below. We compare a range of deals so you can find the best SIM only contract for your requirements.

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SIM Only Deals: The Basics

Let's start from the very beginning. Mobile operators traditionally offer two kinds of contract. The most common contract is usually known as a pay monthly contract, and this includes a mobile phone as well as a pay monthly plan. A SIM only plan, on the other hand, offers you only the pay monthly plan, so you don't get a mobile phone included in the package. This is one of the most cost-effective ways to run a mobile phone.

SIM Only: The Good and the Bad

The big advantage of going with a SIM only contract is that it's going to be cheaper. The monthly cost of your phone plan will be less on SIM only. Why? Because while mobile operators subsidise phones bought on pay monthly contracts, the phone you get isn't free, you pay a little extra each month to cover the cost of the phone. That means that if you've already got a great phone and don't need a new one, or you're willing to shop for a new phone yourself, then SIM only is going to be your best (and cheapest) option.

The rather obvious downside of all this is that you're not getting a new phone. If you don't already have a phone to use and you opt to go SIM only, then you're going to need to buy one. The problem with this is that you may end up paying more for the phone you buy yourself than you would if you just signed up for the standard phone contract. Very basically, if you've already got a phone you are happy with or you're getting a great deal elsewhere on the handset, then SIM only is the way to go, if not you might want to go for a phone contract. And remember you can always use our SIM Only vs Contract Phone Calculator to pick a winner.

Shopping for a SIM Only Contract

The rules for shopping for a SIM only contract are similar to those for shopping for any other kind of mobile contract, though you're not going to need to worry about the quality of the phone you're getting since you won't be getting one. A SIM only plan is just a minutes, texts and data allowance, so you'll need to opt for a certain number of calling minutes, text messages and a mobile data limit. Or if you're just looking for mobile data many networks offer data only sim deals.

While calling minutes and text messages are pretty cheap (and prices don't vary too much amongst operators) mobile data does vary a little more, which means that data is going to be the main thing that you need to look for. You want a decent amount of data, so you don't go over your limit (which gets pricey fast) but you don't want so much data that you never use all of it and are stuck paying for a service that you're not using.

The best plan for choosing a data limit is to take a look at your old mobile bills since most operators list the amount of data you use each month. You can then make a pretty good estimate for the kind of limit you need. There's another data issue, though…

3G or 4G SIM Only Deals?!

Some UK networker operators are now offering two kinds of data plans, and you'll need to choose which you want. 3G plans are cheaper and available all over the UK. However, 4G plans will give you a faster mobile internet (as long as your phone is 4G capable) which can be pretty tempting. Don't forget that you'll pay more for 4G though, plus not all operators have a 4G network, and not all areas of the UK have 4G coverage. If in doubt, check out your chosen operator's coverage checker.

Using Your Phone on SIM Only

When it comes to actually using your phone on your new phone plan, there are a couple of things that you're going to need to keep in mind. Firstly, is your phone unlocked? If you originally got your phone from a mobile operator, there's a fair chance that the mobile will be locked to that operator and won't accept a SIM card from any other company. Fortunately, unlocking phones is relatively straightforward (ask your operator, they may be able to do it, if not find a mobile unlocking company close to you) and is completely legal in the UK.

The other concern is the size of the SIM card. Most older phone models use a large, traditional SIM card, while new models use smaller micro SIM cards. You'll need to ensure that you're getting the right kind of card for the phone that you're using. Luckily, most operators offer something called a combi or multi-SIM, which is a combination of both sizes and can be snapped apart and put back together depending on which size you need. It is best to make sure that you know what you're getting when you sign up, though.

SIM only plans can be a great and affordable option for some users. Finding a plan should be pretty easy, and aside from a couple of concerns like SIM card size, there is no difference between SIM only shopping and contract phone shopping. You might find that SIM only plans save you cash, and that's pretty important these days.

Do SIM Only Deals Require a Credit Check?

Yes, most SIM only deals will require you to pass a credit check. However, there are some no credit check options available with several networks offer deals that don’t require credit checks. What’s more, they’re actually very good value. You can check out some no credit check SIM-only deals right here. These tend to be short-term with the option to cancel or upgrade/downgrade at short notice.

Should you get a SIM only deal?

SIM-only deals are great if you already have a handset you love and don't want to change it. Or perhaps you have snagged a bargain on eBay for a handset outright and needed a SIM card for it.

SIM only plans are also perfect for customers who have bad credit and want to rebuild their credit rating. This is because there is no phone included and this reduces the risk for the phone retailer or network provider. If you take out a SIM only deal and make repayments on time, you begin to rebuild your credit rating. This makes getting a phone contract much easier later down the line.

Many of our customers choose a SIM only deal when they have several phones for different purposes. If you spend a lot of time in the outdoors or work on a building site then a SIM only deal means you can keep an inexpensive handset for when you're out and about. Rather than risk having your iPhone getting covered in dust or dropped down a cliff you can just take a cheaper model out with you.

Is SIM only cheaper than a phone contract?

In most cases, yes, a SIM only deal combined with a handset bought outright will come in cheaper than a contract. However, this isn't always the case especially on smartph0nes that are a year or two old or less desirable than the latest flagships from Apple and Samsung. Our SIM Only vs. Contract calculator will quickly work out which is cheaper over 12, 24 or even 36 months.

What's the difference between pay as you go and SIM Only?

The difference between PAYG and SIM only is that a sim only contract includes an allowance for calls, texts and data which you'll be billed for every 30 days. A Pay as you go SIM card requires you to top up in advance and each call, text or megabyte of data is charged from your balance. However, most pay as you go sim offerings now come with bundles, where you can prepay for a set amount of data, texts and minutes which lasts you 30 days these are known as prepaid sim only or rolling 30-day sim only contracts.

Why would you buy a SIM free phone? Isn't a free phone with a contract better?

When you take out a contract, the phone isn't free. The cost of the handset is factored into your monthly bill. So the reason you'd buy a SIM free phone is a financial one. In most cases buying a sim free handset outright and pairing it with a SIM only deal will work out cheaper than a traditional phone contract. There are of course exceptions to the rule but make sure you run the numbers to see which works out cheaper over the course of 24 months.

What Size of SIM Card Do I Need for My Phone?

There are three sizes of SIM card available for mobile phones these days, though the largest of these are being phased out and won't be used on a newer phone model. Which size of SIM you need depends on the phone you have. Looking in your phone's user manual (or checking online with the manufacturer's website) will tell you which size you need.

There are two pieces of good news though. The first is that most operators have what's known as “triple SIM” cards, meaning they provide you with a SIM card of the largest size which has “pop outs” of the two smaller sizes. You just press out the card size that you need. Should your operator not provide you with one of these you can contact them to get a free replacement SIM in the size that you need.

Is a 30 Day or 12 Month SIM Only Contract Best for Me?

That really depends on you. A 30-day contract is great if you don't like commitment since you can cancel or change your plan at any time. Plus, in some cases, you won't need to undergo a credit check. However, 12-month contracts tend to be slightly cheaper, so if you can commit it could be worth signing up for a longer period. You will find that whilst some operators offer both kinds of contracts, others only offer one or the other, so depending on your preferred network you might be forced into a contract length.

Which Network Has The Best SIM Only Deals?

The standard prices of mobile operators tend to be very similar, however, many offer special deals which change all the time. This means that it's impossible to say that one operator or another will give you the best deals. If you want to find the cheapest deal that fits your needs your best bet will be to use our comparison tool that allows you to see which operators offer the kind of plans you need for the budget you had in mind. We update it daily so the latest offers are always available.

What Do I Need to Do If I Find the Deal I Want?

Sign up! Seriously though, there are a couple of considerations. Firstly, be sure that this is the deal you want, a phone contract can last a long time and the penalties for breaking a contract can be expensive. Secondly, think about whether you want to keep your phone number or not (see “how do I keep my number?”). Thirdly, make sure you're actually eligible for the deal. Will you pass a credit check if one is necessary? Do you still have an open contract with another operator? Only once you've dealt with these concerns should you click on the “buy” button.

Can I Upgrade to a Pay Monthly SIM Only Deal?

Possibly. If you're currently on PAYG then upgrading to a pay monthly SIM only deal should be no problem with any operator. If you're currently on a pay monthly contract, then you might have more of a problem. If your pay monthly contract comes with a phone you'll need to ensure that the phone is paid off (or be prepared to pay off the phone in a lump sum) before upgrading. If the term of your pay monthly contract has not yet ended you may have to pay a penalty before being allowed to change to a pay monthly SIM only deal.

You can find out this information by checking your account with your current operator online, or by calling customer service for your operator.

Can I Get a Deal for My Tablet? How Does it Work?

Absolutely. Most operators offer special SIM only deals just for tablets that contain a healthy monthly data limit. To take advantage of this just make sure that your tablet will accept a SIM card and runs 3G (i.e. it's not a WiFi only model) and sign up for a deal. A tablet SIM only deal works in the same way as your mobile deal does. You get a SIM card, a monthly data limit, and a monthly bill. All you need to do is plug that SIM in and go.

Technically you could probably use a regular mobile SIM only deal for your tablet, but this isn't advisable. A mobile SIM only deal includes not only a data limit but also calling minutes and text limit, neither of which you'll need on a tablet. There's no point in paying for services that you're not going to use.

Can I Trust Smaller, Less Well Known Networks? Is the Service as Good?

People do get understandably worried about using lesser known operators, but in general, you shouldn't be concerned. Smaller networks (known as MVNOs) don't have their own infrastructure to provide service. Instead, they rent infrastructure from one of the large networks. So, for example,  Sky Mobile rents infrastructure from O2 to provide service. This means that if you sign up for Sky Mobile you'll get the same coverage and standard of service as you would from O2.

Smaller networks are often cheaper than larger ones (since they didn't need to spend money building infrastructure), whilst providing the same standard of service. However, smaller networks do have their own customer service centres, and their own deals for phone models, which may or may not be as good as with a larger operator.

I've Found a Good SIM Only Deal with My Existing Network. What Happens Now?

As long as your current contract with your operator is at an end (or within the grace period that allows you to change the contract) this should be no problem at all. You should call your operator to ensure that you're allowed to change to a SIM only deal, and once you are, go ahead and change. Depending on your operator there may be a period where you're still on your old contract, and you may or may not get two bills in the first month (one for you old contract, one for your new). Again, it's best to check on this with customer service first.

I Want a SIM Only Deal with Another Network. What Do I Do?

If you want to keep your mobile phone number you'll need to take care of that first (see “how do I keep my number?”). Once you've done that you'll need to cancel your old contract and sign up for your new one. In general, it's best to sign up for the new deal first to ensure that there aren't any problems with cancelling your old contract. However, some operators will have a “notice period” before a contract can be cancelled. Call your old operator and ask how their contract cancellation process works and how long it takes before deciding whether to cancel first or not.

How Do I Keep My Number?

Keeping your mobile number is pretty simple, but you do need to start this process BEFORE cancelling your old contract/service. Simply call your current operator's customer service line and request your “Porting Authorisation Code” or PAC. The company is required to give you this information when requested, though it may take several days to arrive by email or mail.

When you have your PAC, go to your new operator and sign up for a contract, requesting that you keep your old number. If you're signing up online there should be a step that asks you if you want to do this. You'll need to give your PAC to your new operator, and that's it, the operator will do the rest.

What Do I Do with My Old SIM?

If you no longer need an old SIM card, you can throw it away. However, since a SIM card does contain data about you, it's best to destroy it first. Take out the SIM card from your phone and use scissors to cut it into pieces. Make sure that you cut across the small bronze square at least once (since this is the chip that contains your info). Once you've cut it up, you can safely throw the pieces of your old SIM away.

What Networks Offer SIM Only Deals?


BT Mobile offers a range of SIM only plans with both 3G and 4G data. An MVNO, BT Mobile uses the network of operator EE to provide service. All plans include unlimited calling minutes and texts. If you're an existing BT Broadband customer then you'll get discounts on SIM only mobile packages. BT Mobile also offers SIM only family plans that give savings for multiple SIM cards on one account and the convenience of just one bill for all your family phones. Compare BT SIM Only Deals.


EE has a variety of SIM only contract options, including 30-day contracts, all of which offer fast 4G mobile data. The operator has some of the highest mobile data limits around, making them a good choice if you're a big mobile internet user. All plans have unlimited texts, and most have unlimited calling minutes too. EE also gives you 6 months access to Apple Music on sign up, and has data caps to prevent you accidentally going over your mobile data allowance. Compare EE SIM Only Deals.


Freedompop is an unusual operator since they don't actually use a mobile operator network. Instead, all calling and texting uses WiFi. This allows the company to have exceptionally low rates (starting from you paying absolutely nothing). Currently, not all areas of the UK have access to Freedompop's network. All deals with Freedompop are SIM only (and have no contracts), and all include unlimited texts, calling and WiFi data. However, you will need to check with the operator's website to ensure that you have access to the service in your area.


Giffgaff have a range of simple SIM only plans, all containing 4G data as the default. The company is an MVNO and uses O2's network to provide service. There are no contracts with Giffgaff, and all SIM only plans are 30-day ones, meaning you can cancel anytime. Plans go from limited small user plans for just £6 a month, all the way up to completely unlimited plans. Giffgaff also offers payback rewards, where you collect points for recommending the service to others. These points can be converted to cash, credit, or a charitable donation.


As an MVNO, iD uses Three's mobile network infrastructure to provide service. The company offers a range of SIM only plans both big and small, all with 4G mobile data. All contracts are 30-day rolling plans, meaning you can cancel or change your plan at any time. Plans also all include data rollover, so you can push your unused data into next month should you need to. The company also offers bill capping, so you can limit how much your monthly bill can be, meaning no unpleasant surprises! If you're looking for low-cost phone service, iD is an excellent choice.


O2 is the second largest operator in the UK and offers fast 4G mobile data as well as 3G services. They have plenty of SIM only plans to choose from, with both 12 month and 30 day contracts available. You can also add bolt-ons to your chosen plan if you decide to add a little extra data to your contract. With O2 you'll get discounts for combining your mobile service with a home broadband service, as well as regular daily deals that give you discounts on cinema tickets, for example, and chances to win phones and other gadgets. Compare O2 SIM Only Deals.


Plusnet is a UK based mobile operator, and as an MVNO uses EE's network to provide service. They have plenty of SIM only plans to choose from, all of which include international roaming for the same price as UK service, and access to fast 4G mobile data speeds. There's also the possibility to add a bolt on to your existing plan to give you extra minutes, texts or data should you need to. Plusnet's SIM only plans are no contract, so you can change or cancel your plan at any time. They also offer caps so that you can limit the amount of your monthly bill and not get any surprises! If you're a Plusnet home broadband user, you'll get discounts on mobile plans too. Compare Plusnet SIM Only Deals.

Sky Mobile

Sky Mobile are an MVNO owned by the Sky television company and use O2's network to provide service. They offer a variety of plans, all with different mobile data limits, and you can change your plan whenever you'd like. Sky Mobile has both 3G and 4G mobile data coverage. If you're an existing Sky customer you'll get discounts on your mobile service. Sky Mobile also allows you to roll over your leftover mobile data to the next billing month if you like and offers family plans letting you save money and have just one monthly mobile bill. Compare Sky Mobile SIM Only Deals.


Smarty is an MVNO that uses Three's mobile network to provide service. They're renowned for being a simple network to use. All their SIM only contracts are 30-day plans, so you can change or cancel when you wish. All plans have unlimited calling and texting. And if you don't use up your monthly data limit, a discount is given on your next mobile bill. You can add add-ons to your plan should you need any extra mobile data, and data is available in both 3G and 4G. Currently, roaming and international calling are not available on Smarty, but these features are coming soon. Compare Smarty SIM Only Deals.

Tesco Mobile

Tesco Mobile is an MVNO owned by the Tesco shopping brand which uses O2's network to provide service. You'll get 4G data as standard, and contracts are available in 12 month or 30-day forms, giving you flexibility. There are plenty of different plans to choose from with Tesco Mobile, including affordable family plans. You can also cap your monthly spending to prevent spending too much. Tesco Mobile offers great parental controls for kid's accounts too. Compare Tesco Mobile SIM Only Deals.

The People's Operator

As an MVNO, The People's Operator uses the network of operator Three to provide service, including their fast 4G mobile data services. All contracts with TPO are 30-day rolling contracts, so there's no credit check and you can change or cancel your plan whenever you like. All plans include unlimited texting, and there are add-ons should you need any extra monthly data or calling minutes. The People's Operator donates 10% of your monthly payment to a charity of your choice.


Three are famous for being one of the best UK operators for mobile data and offer 4G as well as 3G service. They are one of the few operators that have an unlimited data plan (although not all plans contain this). Three offer both 12 month and 1-month contracts and the company guarantees that you will not get an unexpectedly large data bill. With Three you can also stream services such as Netflix without using up your mobile data limit. Compare Three SIM Only Deals.

Virgin Mobile

Virgin Mobile is an MVNO that uses EE's network to provide service. All their plans include fast 4G mobile data and unlimited texts. The company offers 12 month SIM free contracts, but allows you to change your data limit at any time should you need more (or less) mobile data. You can roll over any unused data to the next month. Virgin Mobile also lets you use services such as WhatsApp and Facebook Messenger without using any of your data limits, and has no mobile roaming charges in 43 countries across the world. Compare Virgin Mobile SIM Only Deals.


Vodafone is the third largest mobile operator in the UK. They offer a wide range of SIM only plans on both 12 month and 1 month contracts, all of which include fast 4G mobile data. On a 12 month contract you can change your plan after the first 3 months if you find you need different data, texting or calling limits. You can add a variety of Vodafone Passes to the contract that allows you to use certain apps (such as WhatsApp or Netflix) without needing to use your mobile data. And Vodafone offers no roaming charges in 110 different destinations. Compare Vodafone SIM Only Deals.


Voxi is an MVNO that uses Vodafone's network to provide service and specialises in data for social media. They offer a range of SIM only plans, all on 30 day contracts, allowing you to change or cancel your plan whenever you like. All plans have unlimited texting and calling and fast 4G mobile data, and all allow you to use social media apps such as Facebook and Snapchat without using up your mobile data limit. You'll also be able to use your phone anywhere in Europe for no extra charge and be rewarded for recommending the operator to friends or family. Compare VOXI SIM Only Deals.

If you have any questions relating to our SIM only deals and whether they're right for you then feel free to contact us for advice.