How to choose a SIM only deal that's right for you
Dan Howdle • September 26th, 2024
The UK mobile market is awash with SIM only deals, from the tiniest amount of data to a wealth of unlimited deals. So where do you start when it comes to looking for a new one? If you already have a phone and you’re at the end of your contract, you may decide to stick with your current provider and get a new SIM deal with them, but with so many offers out there it’s always worth taking a look around first.
There are several things worth thinking about when choosing a SIM only deal, from which provider has the best coverage in your area to the amount of data you think you’ll need. In this guide we’ve outlined all you need to know when shopping for a new SIM deal, so you can be confident you know exactly what you are looking for.
What is a SIM only deal?
A SIM only deal is where you buy an allowance of data on a SIM card for use in a phone you already have. Whether you have bought a new phone outright and want to find a SIM deal for it, or whether your current handset contract has run out and you are looking to get a cheaper data deal, a SIM only deal is what you will need.
Don’t be put off by the prospect of switching to another provider as it’s simply a question of requesting a PAC code in order to be able to keep your number. If you’ve bought a brand new phone or got hold of one second-hand and this is your first SIM only deal purchase, you’ll have no worries about keeping your number as you will be given a new one with whichever SIM you choose.
Choosing a network and a provider
In this country there are four mobile network operators; namely O2, EE, Three and Vodafone. These are the four companies that own and control the infrastructures that supply us with a mobile signal. As well as the networks themselves, there are a number of what are known as MVNOs (Mobile Virtual Network Operators). These are businesses that rent the network capacity from the network owners in order to provide their own mobile services.
This includes such familiar names as Tesco Mobile (which runs on O2), Asda Mobile (Vodafone), iD Mobile (Three) and Sky Mobile (O2). In some cases, networks own and run their own MVNOs, such as Vodafone, which owns Voxi, Three, which owns SMARTY, and O2, which owns giffgaff.
Whether you sign up directly with a network or with an MVNO will make no difference to the quality of your connection, and invariably the MVNOs tend to offer cheaper deals than the networks themselves.
Network coverage and speeds
All four networks claim to cover over 99% of the population when it comes to 4G services, which will give you pretty reliable connectivity wherever you are, regardless of your network, although inevitably there are some blackspots in certain areas.
According to the most recent report from consumer research group Opensignal, EE continues to lead in overall mobile network experience, offering the fastest average download speeds and the best overall mobile gaming experience. EE also ranks highest in 5G gaming and video experience. When it comes to 5G download speeds specifically, Three leads the way with an average 5G download speed of 265.8 Mbps, followed by EE at 204.3 Mbps, Vodafone at 150.1 Mbps, and O2 at 100.3 Mbps.
All four operators are gradually extending their 5G coverage across the country but it is still primarily limited to towns and cities. According to Opensignal’s research, Three and Vodafone both share the best 5G availability, with EE and O2 trailing behind.
Contract lengths
Most mobile providers offer a choice of one-month, 12-month or 24-month contracts for SIM only deals. Once you’ve decided on how much data you want, if you can commit to a longer contract, you are likely to get a better deal and pay less for the same data than if you chose a contract-free option. On the flip side, if you don’t want to commit, a 30-day deal gives you the flexibility to leave when you want.
How much data do I need?
This is a bit like asking how long is a piece of string, as it really depends on your own situation and how much data you use. Generally, there are three categories of users which we’ve summarised here.
High usage
If you are rarely connected to wifi and constantly use your phone to stream video or audio, then an unlimited data option is likely to be the best choice. As well as giving you all the data you need to play with, it also gives complete peace of mind, knowing that you will never run out and you won’t be charged for any excess usage either.
If you like to be able to tether your phone to a laptop, for example, or if you like to have the option to share data with others, note that these uses of your data are unlikely to be unlimited too. Most unlimited plans come with a limit when it comes to sharing or using your phone as a hotspot, but it’s often in the realm of 100GB, so still plenty for most people’s needs.
Medium usage
If you use your home or work wifi a fair amount, but like the flexibility to use your mobile connection when you want, then you will benefit from a fixed but generous amount of monthly data. If you sometimes find that you need a data connection on a long journey, for example, or if you are intermittently away from wifi, then a chunk of data greater than 11GB but under 100GB should suit.
Most providers tend to offer data amounts in this region, so depending on how much you are away from wifi, and how much streaming you do, one of these will fit the bill. If in doubt, plump for a smaller allowance as you can always increase it if you want to. You cannot, however, lower your monthly amount of data if you sign up to a contract that is for longer than a month.
Low usage
If you are connected to wifi most of the time, either at home, at work or at someone else’s house, then you will only need a very small amount of data to tide you over on those occasions when you are without wifi.
Some providers still offer minute amounts of data, such as 1GB, but in most cases the entry-level allowance is 10GB. If you feel you need a little more than that, then there are plenty of 25GB and 50GB deals around that should keep you covered.
Data only SIMs
If you are looking for a SIM only deal for a tablet or mobile hotspot device, then there are a number of data only SIMs available. Unlike phone SIMs, these come without a texts or minutes allocation and are designed for getting online when you are away from wifi. As with phone SIMs, data only SIMs come with a choice of data allowances, from 1GB to unlimited, and a choice of contract lengths.
Which providers offer data only SIM deals?
The four main networks – EE, Vodafone, Three and O2 – all offer data SIMs for use in tablets, laptops and MiFi (hotspot) devices. They are also available from several other operators including Smarty, Asda Mobile and iD Mobile.
Contract SIMs vs PAYG
There are two main advantages to getting a contract SIM rather than going Pay As You Go. The first is that it’s often cheaper – quite simply, you’ll get more data for your money. This is especially the case with top-up SIMs where you just pay for credit on your account when you need it and you are then charged for every minute, text or MB used.
Many providers offer PAYG bundles, which offer better value than top-up and much the same data allowances as a postpaid contract SIM deal, but still quite often at a marginally higher price. You can also set up a direct debit so that your PAYG bundle renews every month if you wish.
The only downside of a contract SIM is that you have to undergo a credit check beforehand, so if you think this might be a problem, then a SIM only PAYG bundle deal is a good alternative.
