SIM only deals are a great option for many people in the UK and one that has rapidly become more popular. As people begin to hold onto phones for longer, the value of SIM plans has become obvious.
Whether you've got the cash to buy a SIM-free phone, you've got a contract that's ended or you've picked up a cheap second-hand phone somewhere, investing in SIM only deals is a great way to keep the costs low.
And the great news is that there is a load of choice out there. While the obvious choices remain with EE, Vodafone, Three and O2, there are now a host of smaller names known as MVNOs offering unique selling points.
Voxi for example can give you unlimited use of social media, many operate on 1-month rolling contracts allowing you to leave at any time, some come with reward schemes and others are just really cheap.
In fact, the main issue with SIM only deals these days is trying to work through all the many options to work out which one is best for your current needs and luckily, we've made that process a bit easier.
In these guide, we've picked out the top 10 SIM plans and answered all of the obvious queries you might have.
Three | 12-month contract | All-you-can-eat data | Unlimited calls and texts | £18 per month
Three has offered the best SIM plan on the market for quite a while now. It costs just £18 a month while offering unlimited data, calls and texts. This is the UK's cheapest price on unlimited data undercutting all of the other plans out there.View Deal
What is a SIM only deal?
A SIM only deal is a contract that rewards you with a SIM card. When you choose a SIM plan you decide the data, calls, texts and network that you are on as well the contract length and price you are willing to pay.
Who has the best SIM only deals?
- Three: best for big data and unlimited plans
- EE: best for fast speeds and overall performance
- Vodafone: strong balance of affordability and features
- O2: heavy on the added benefits
- Smarty Mobile: best value 1-month rolling option
- Voxi: best for social media users
SIM only deals of the week: top 10
1. Best cheap SIM plan
Lebara SIM only | 1 month contract | 2GB data | 1000 minutes and texts | £5 per month
Lebara is one of the cheapest providers of SIM plans out there and thrives best at low prices. This deal for example provides you with 2GB of data for just £5 a month. That is a price that can only really be matched by iD Mobile.
Score 2GB of data at a low price with Lebara
2. Best 5GB+ data SIM
iD Mobile | 1 month contract | 9GB data | Unlimited minutes and texts | £9 per month
iD Mobile is a brand synonymous with affordability and this plan supports that well. For £9 a month, iD can supply you with 9GB of data. That's plenty for most people's casual streaming needs, supplying enough to catch up with a bit of Netflix streaming, some social media and plenty of Google searches each month.
Check out this excellent value iD SIMO
3. Best 30-day SIM plan
Smarty | 1 month rolling | 30GB data | Unlimited calls and texts | £10 per month
Smarty just keeps going all out on affordable SIMs! With this plan, you're paying just £10 a month to get 30GB of data. That's an excellent price to be paying, especially when you consider the fact that Smarty operates on 1-month rolling contracts meaning you can leave at any time.
Get this amazing SIMO price from Smarty
4. Best big data SIM (20GB+)
Smarty | 1 month rolling | 50GB data | Unlimited calls and texts | £15 per month
Smarty has a number of affordable plans but this is the best. It is currently offering double the data, securing you 50GB each month but it only charges you £15. On top of the high data cap and low costs, Smarty operates on 1-month rolling contracts so you can stay for as long as you like or leave at any time.
5. Cheapest SIM only deal for unlimited data
Three | 12-month contract | All-you-can-eat data | Unlimited calls and texts | £18 per month
This plan from Three sticks out as the best deal around for SIM cards right now. It provides unlimited data, calls and texts for just £18 a month. That is far cheaper than any of the competition unlimited data SIMs out there, making it easily the best price available.
See Three's best SIM only deal in full
6. Best value EE SIM
24 months | 100GB data | Unlimited calls and texts | £20
Has EE finally got competitive with its pricing...with this deal, it looks like it has. For the price of £20 a month, you're getting a massive 100GB of data. While that is already pretty affordable, it gets better considering EE will charge you half the amount for the first three months of your contract.
Get the best value EE SIMO deal out there
7. Best cheap Vodafone SIM
12-month contract | 60GB data| Unlimited texts and calls | £16 per month + £54 cashback by redemption
This deal on Vodafone gets you 60GB of data while only charging £16 a month for it. While that alone is an excellent offer, it gets even better. Vodafone is also throwing in £54 in cashback, effectively bringing the costs you're paying down to just £11.50 a month - a market-leading plan.
Click here to get this great value Basics SIM from Vodafone
8. Best O2 SIM only deal + free Disney Plus
O2 | 12-month contract | 100GB data | Unlimited calls and texts | £20 per month + Disney Plus for six months
O2 has really stepped up its game of late and of all of its latest options, this one is the standout. Offering 100GB of data for just £20 a month. Alongside the data package, O2 will also throw in a free six month subscription to Disney Plus.
Check out O2's big data + Disney Plus subscription deal
9. Best SIM for social media users
Voxi | 12-month contract | 12GB data | Unlimited calls and texts | £10 per month + free social media usage
Find yourself powering through data because of social media apps? Voxi is likely going to be the best network for you. With this plan, you get 12GB of data while only paying £10 a month to get it. On top of that, Voxi doesn't use up any data when using social media apps. That means you can use Facebook, Whatsapp, Twitter and more without fear of running out of data.
Check out Voxi's cheap SIM deal with free social media
10. Best data only SIM deal
Three | 12-month contract | 10GB data | £14 per month
If you use your tablet as a kind of portable TV for catching up with Netflix, iPlayer and Amazon Video while out and about, then this Three data only deal just got even better. You now get 10GB for £14 a month (sorry, it has just gone up in price), which is cheaper than other major networks. This is the best value SIMO we can find for using data on an iPad or one of the other best tablets.
Should you get a SIM only deal?
Should you get a SIM plan?
If you a) want to save some money; b) don't want to be tied into a lengthy contract; or c) both of the above, then SIM only is well worth considering. In fact, you're probably one of two people if your thoughts are indeed turning to SIM only:
- You're coming to the end of your contract and your network is calling you a million times a day to get you to upgrade. Well if your phone is dying a death or you just fancy a change, head to our best mobile phone deals page to see what bargains are lurking, but otherwise going SIM only on your current phone is a no-brainer. You'll wind up paying much less than you are under contract, and you can stick to a rolling 30 day contract so that if your circumstances change, you can get out of the arrangement tout suite.
- It's time for a shiny new smartphone and you want to get the best value humanly possible. You'll have to find a few hundred quid up front for the handset (be sure to check our SIM free price comparison tool) but box clever and you'll end up paying less over the next 24 months (see below). Plus, if you're a commitment-phobe, most SIM-only plans don't require you to sign up for two years like you would with a normal contract.
Is a SIM plan cheaper than a phone contract?
It can be. Teaming a SIM only plan with a SIM-free phone could save you a few quid, especially if you catch a big discount. It's usually the case when a flagship phone hits the market and contracts are made deliberately expensive.
Not all the savings you can make are as extravagant, and on big data it's frequently more cost effective to dive into a contract instead. But if you can afford to splash a few hundred pounds up front then the savings over the next couple of years could well be worth it.
What kind of SIM plan do you need?
Is my phone unlocked and can I use a new SIM in it?
The times have passed since most phones were locked to a network and you had to pay a dodgy backstreet 'engineer' to unlock it. Nowadays, it's standard practice for networks to let you use whatever SIM you want in the phone as soon as you've paid up the original contract (or earlier if you pay them a fee) - and Three ships all its handsets unlocked from the outset.
The good news is that if you're phone does turn out to be locked to a network, it is easy to fix that. The bad news is that most networks make you pay for the privilege. Insert a friend or family member's SIM into your phone to see whether it's already unlocked and, if it isn't, look for your network below to see how to cut ties with them:
- EE Once six months have gone by on your contract, you can call EE on 0800 956 6000 and pay them £8.99 to unlock your phone. It says it will take around 10 days to complete. PAYG phones can be unlocked for free. Both iPhones and Google devices unlock for free after a certain time with EE.
- O2 Whether you have an iPhone or Android device, pay as you go or on a contract, O2 can unlock it for free. You simply need to log into the O2 app, select unlock my phone and you're good to go.
- Three Fear not, all phones on Three are unlocked as standard. Shove whatever SIM you like in there, it will work a treat.
- Vodafone The red network doesn't quite get the same marks as Three, as your phone will be locked to them on arrival. But they have made unlocking handsets absolutely free within 10 days of your request.
What SIM card size do I need with SIM only deals?
It used to be the case that you would need to do some detailed research to see which size SIM card you would need for your phone but recently most networks switched over to Combi SIM cards.
These are SIM cards that are all three sizes and you simply break it down to the size you need. While that sounds fiddly and complicated it is actually extremely simple.
If you do come across a network that does not use these Combi SIM cards, there are three sizes:
- Standard (15x25mm) - Micro (12x15mm) - Nano (8.8x12.3mm)
The majority of recent phones, especially flagships, now use Nano cards.
Can I get 5G SIM only deals?
Yes, you can! As part of the 5G movement, a number of networks have started offering the possibility of getting enhanced speeds and latency with 5G SIM only deals. Right now both Vodafone and Three offer 5G and 4G on all of its plans, it simply depends on whether your phone is compatible.
There are a number of 5G compatible phones out there (you can see the top ones with our 5G phone deals guide).
As for EE, you will have to pay more to get your 5G SIMs, with a premium added cost involved.
What length contract should I get with SIM only deals?
There is a good few options when it comes to the length of SIM only deals. While the most common option you'll see is 12 months, there is now a wide range of 30 day SIMs as well from the likes of Voxi, GiffGaff and Smarty.
There is also the occasional 24 month contract but these are a lot more rare than the above. These do often offer discounted prices though if you're willing to stick around for longer.
How much data do I need?
Because you can change your plan up more regularly than a normal, lengthier contract, it's less crucial to get this nailed from the start. But if you're thinking of grabbing a 12-monther or just put a personal pride on getting things right first time, then we'll help you pick out the sweet spot of data for you.
Firstly, check your phone to see how much data you've been using to date, and whether you have the tendency to use more than your current allowance every month. Then, if you're still unsure, check out our guidance:
- 0-1GB Tiny amounts of data could be a blessing or a curse. If you're putting it in a rarely used phone that will scarcely be away from wi-fi then you're quids in. But if you end up with one because your head's turned by the incredible price, then you could end up paying more if you continually go over your allowance.
- 2-3GB For anybody who needs data for little more than the occasional Google Maps route planning, 2GB and 3GB plans come cheap and give you much more freedom to check the football scores and scroll Facebook away from the wi-fi without danger.
- 4-8GB If you can't leave the house without having a music streaming service like Spotify pouring into your ears, then it might be worth paying for some extra GBs of data.
- 10-16GB This is a significant amount of data and some networks offer it for a very appetising price. Whether streaming music, downloading podcasts, watching social media videos, or all three is your thing - you should be covered.
- 20-30GB Only smartphone junkies that need regular (and hefty) data fixes need bother with this avalanche of GBs. You'll be able to rinse Netflix, Spotify and online games without too much fear of topping out.
- Unlimited Maybe it's because you use remarkable amounts of data. Maybe it's because you simply don't want to keep checking how much data you've used every month. Whatever your reason to go unlimited, you have only two choices when it comes to network: Three or GiffGaff.
Do I need unlimited calls and texts?
This question is practically obsolete now as the large majority of SIM only deals will provide unlimited calls and texts anyway. For the small amount that don't, you'll likely be getting in the range of 500-5000 minutes and a few thousand texts.
Due to the fact that these kind of contracts are rare, we wouldn't worry too much. If you do come across one with a smaller cap and it feels right for you, take a look at how many texts and calls you've used in the past.
What's the best mobile network for SIM only deals?
While EE, O2, Vodafone and Three are generally considered the major four networks for contract plans, when it comes to SIM only there are some other key players are well worth a look. See what we think of them below, and whether you'll get any free perks to help persuade you to sign up. Plus, we'll tell you about a couple of other SIM sellers that might be able to wrangle you an even better deal.
Which networks have coverage in my area?
It's one of life's (many) little frustrations - you sign up with a network, get your SIM up and running and then discover that you get no coverage at all in your house. Well this little pain in the neck can be avoided by using the dedicated coverage checker that most networks provide. Enter your postcode and you'll see whether your address has 2G (calls, texts and email), 3G (the basics plus picture messaging and faster web browsing) and 4G (all the powers of 3G, plus faster downloads, online gaming and media streaming) coverage.
Switching to a new SIM plan:
How do I keep my old number?
Ever heard of PAC codes and wondered what a classic 80s arcade game had to do with telephone numbers? It actually stands for Porting Authorisation Code, and it's the set of digits that you need to grab from your old network to let you transfer over your existing mobile number.
The great news is that the process is a lot easier these days. Now you can text your provider and they will text your pac code back to you. They have to reply within a minute and the code will last for a full 30 days.
You then give your code to your new provider and your number has transferred. You can find out more with our guide to Text To Switch.
SIM only deals by network
EE SIM only deals:
If you want fast and furious 4G, then your choice has to be an EE SIM deal. Its speeds are around 50% faster than the other major networks, which is really noticeable if you like watching films or football on the move. And EE gives you three free months of BT Sport, as well as six months of Apple Music and a host of other free subscriptions.
Head straight to EE to see all of its best SIMs
O2 SIM only deals:
O2 has a lot to offer. Along with the fact that many of its plans lead the way for pricing, it has recently started offering a six months subscription to Disney Plus across a number of its best plans. On top of that it offers free Wi-Fi hotspots across the country, great coverage and its Priority rewards app with discounts, free tickets and more.
Vodafone SIM only deals:
Vodafone feels like one of the most well-rounded providers of SIMs. It offers affordable prices on a lot of plans and packs in a number of benefits. Most importantly is its VeryMe app which provides discounts, competitions and a free gift every Friday - the perfect competition to O2's Priority scheme.
Go straight to Vodafone to compare all of the deals
Three SIM only deals:
Three has the major benefit of being the cheapest of the four main networks. It provides the lowest cost on unlimited data, cheap plans and pretty much everything in between. While it no longer has the Wuntu app to compete with Vodafone and O2's reward scheme, it offers great travelling and roaming perks.
Head to Three to see all of its plans.
iD Mobile SIM only deals:
iD is a good option if bargain basement prices are what you covet most. This is a network run and owned by Carphone Warehouse - it piggybacks on the Three network. It's an excellent option if you want great value on a rolling monthly contract.
Smarty Mobile SIM only deals:
Smarty is one of the newer players in the world of SIM only deals but one with a lot of benefits. Not only is it extremely affordable but it also provides tethering abilities and all of its contracts run on 1-month rolling contracts so you can leave at any time. It piggybacks off of the Three network so will have reliable coverage across the UK.
Check out the full range of Smarty SIMs
BT SIM only deals:
That familiar old stalwart of telecommunications BT is so-so when it comes to SIM only tariff prices. That's unless you're already a BT broadband customer, in which case you get some really favourable prices - a fiver less than the rest of the hoi polloi. Plus, you usually get a BT Reward Card with the majority of plans that can be spent anywhere that accepts Mastercard, the value of which depends on how much data you're in for.
Go straight to BT's website to see all of the available SIMs
GiffGaff SIM only deals:
GiffGaff regularly offers some of the cheapest SIMO deals out there. They don't give you much of a data allowance to play with, but if you just want to keep your phone going and available to use for calls and texts with the occasional bit of internet use outside of your home Wi-Fi, GiffGaff is a strong offering. Look out for the T&Cs though as some of the big data deals throttle the speed after a few gig.
You can go straight to GiffGaff to see all of the deals
Virgin SIM only deals:
Virgin Mobile has been going for a long time, and some of its SIM only deals are particularly attractive - especially when it gets going with its brilliant flash sales. It's one of the providers that offers data rollover, a perk we're really very fond of.
See Virgin's full list of SIM packages
Tesco SIM only deals:
The UK's biggest supermarket has been known to offer competitive - if not stellar - SIM plans, with low data prices starting at not much more than a fiver a month. Where it get's really interesting is if you download the Xtras app to an Android phone: you'll save £3 on your monthly bill, but you will have to see adverts every time you unlock your handset.
See Tesco's full collection of SIM deals
Plusnet SIM only deals:
Plusnet might be more well known for its broadband deals these days. but it's also keen to push some very cheap 30-day SIM only deals. You don't have to worry about signal either as Plusnet uses EE's network that covers 99% of the UK. Plusnet's cheap plans start at around £5 a month.
See Plusnet's full range of SIM only deals
Carphone Warehouse SIM only deals:
Carphone Warehouse doesn't just sell handset contracts. It also has a wide range of SIM only deals for Vodafone, ID and Virgin. The online store is also known to include additional incentives such as half price fees for six months, cashback and the occasional free tech item.
The SIM only deals on this page are checked every day to make sure they're still available and up to date! If you're ready to go SIM only, then head back to the top of this page and use our tool to find the perfect plan...