Find and compare the best SIM only mobile phone deals on the market

Sim only deals come in two different varieties. The most common sim only plans are pay monthly contracts that don’t include a new phone handset. Instead you pay for data, airtime and minutes included on your new sim deal that you insert into your handset, whether this is a new handset you have bought or your current phone that has come to the end of its contract. 

There are benefits to choosing sim only contracts compared to taking out long term phone packages:

  • Sim only deals are cheaper than contracts that include handsets, because you don’t have to pay for the cost of the handset.
  • Sim only plans are more flexible, with innovative operators like Giffgaff and Smarty offering monthly rolling packages that you can change from month to month.
  • Pay as you go sim plans allow you to pay only for the data or airtime that you use, without any kind of contract altogether. When you order your pay as you go sim you will need to top it up with credit, from which your data use, calls and texts will be deducted at the stated rates.

What Is Sim Only?

Sim only deals include a sim card but no phone handset. This means that you will either need to purchase a phone separately or already have a phone into which you can place the sim card. This could be a handset that you have bought separately or one which you bought through a pay monthly plan with another network provider that has come to the end of its contract. The sim card can then be used in any phone (provided it works on your current network or is unlocked). The age of your handset could also determine which type of sim you need. Most modern phones use nano sims or eSims (eSIMS), though when you take out a new sim only plan the physical sim will be sent to you with various sizing options that you can adjust for your handset.

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Best Rolling (1 month) Sim Only Deals

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Many operators offer rolling one month sim only packages as part of their sim only catalogues. Mobile Virtual Network Operator Giffgaff was the first network provider to offer these kinds of sim only deals, providing flexibility and choice to customers. Giffgaff gives customers a choice of Goodybags, which comprise unlimited calls and texts and various amounts of data. Other operators soon followed suit, with each MVNO offering different options and variations on the rolling one month contract concept. The flexibility of these contracts give you the option to switch from one provider to another if you find one network provider’s coverage is more comprehensive in your area, or if you see better deals offered by other networks.

Best 5G Sim Only Deals

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During the rollout of the 5G network, mobile network providers labelled 5G sim only plans as 5G ready, making the point that you will also need a 5G handset like the iPhone 12 or Google Pixel 5 in order to take advantage of 5G sims. All of the major networks offer 5G sim only contracts, including Vodafone, O2 and EE, the latter of which was the fastest network to roll out 5G coverage across the UK. Mobile Virtual Network Operators (MVNOs) like Giffgaff and BT Mobile also offer 5G sim only contracts, meaning there is plenty of choice when it comes to selecting which 5G plan is best suited to your needs. If you are hunting for a 5G Sim only deal make sure your chosen network features 5G sim only packages.

Unlimited Data Sim Only Deals

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Data is the first tick on the list for most of us when we make mobile contract choices, so it is no surprise to see all mobile operators offer unlimited data sim only deals at the top end of their sim only catalogues. Some network operators offer boosts to their plans, like the Voxi sim only packages that offer endless social media as a feature to accompany all of its contracts. These unlimited data offers often double or even triple when it comes to sales events like Black Friday, January sales or summer sales promotions. However, different network operators kickstart their promotions at different times and are always competing against each other, ultimately giving you more choice and better value when it comes to picking the right package for you.


Pay Monthly Sims

Pay monthly sims come with a certain amount of free data, minutes and texts as part of your contract. Different operators offer different terms, providing you with various amounts of free data, from 1GB right the way up to unlimited 5G data sim only plans offered by all of the major networks. Not all MVNOs offer 5G sim only contracts so be sure to check that your chosen network has 5G capability. It would be frustrating in the extreme if you had just purchased a 5G handset like the iPhone 12 or the Samsung Galaxy S21 only to find you couldn’t access 5G network speeds. Conversely, some MVNOs like BT Mobile offer 4G and 5G across all of its sim only contracts, removing that concern altogether.

You have options when it comes to the contract lengths of sim only deals. Even the biggest networks like EE offer rolling sim only contracts in order to compete with the smaller MVNOs like Giffgaff and Smarty that made sim only deals their bread and butter. The EE Flex Plans do just that, offering no strings attached monthly contracts which give you total flexibility as they don’t tie you down for great lengths of time. EE also rents network bandwidth to MVNOs like Plusnet Mobile, BT Mobile and ASDA Mobile, which means you can access the EE network via those providers.

While short term rolling monthly contracts offer more flexibility, the flipside to that coin is that they might not offer the best value. As a general rule, the longer your contract term the better value of the deal. Because you are providing the network operator with more security they are prepared to offer you more in return, whether in lower monthly premiums or more data included in your package. 

Pay As You Go Sims

Instead of pay monthly sim only deals you can also purchase Pay As You Go sim cards (PAYG). Or as well as a pay monthly sim, if you have more devices and are feeling fruity. In fact, some operators offer discounts for additional sim cards or extra benefits when you add further sims to your package. One such example is Sky Mobile and its rollover packages, which allow you to roll unused data over from one sim to the next.

PAYG sims work in a similar way to pay monthly sim deals, but rather than using your phone and eating into your chosen allowance you will first have to top up your sim with credit. The most common ways to top up involve making a payment via your online account, by texting the top up number or through the network’s dedicated app. You can check your data and airtime usage via your handset, and all network operators send you alerts when your balance is running low so you don’t get stuck without mobile data or airtime. You can also introduce usage caps to help you stay on top of your screen time, helpful tools as we all spend increasing amounts of time on our phones.

Network providers sometimes include minimum monthly top up terms on their sim only contracts. All EE sim only packages include data rollover terms with them, though you will have to renew your monthly sim plan in order to access the unused data, which effectively counts as a minimum monthly charge to use the sim only deal. Smaller operators like Plusnet and iD Mobile offer flexibility within their sim only packages, often allowing you to switch plan mid contract. To compete with these offers, major operators have followed suit, resulting in more flexibility for smartphone users.

Can I Save Money With a Sim Only Deal?

If you are coming to the end of a long term phone contract that included the purchase of a new handset then switching to a sim only deal will save you money. For example, your outlay on an EE unlimited 5G data deal that included an iPhone 12 handset would likely be halved by switching to an unlimited data 5G sim only deal. As with any phone contract, whether sim only or pay monthly plan, the cost of the total package is down to your needs. An Ofcom study found that only 27% of smartphone users would lose money if they switched to a sim only contract at the end of their phone plan. Things to think about are:

  • How much data will you need? If you stream live sports or watch shows on your smartphone you will likely use bags of data, which will cost you more. Streaming Netflix shows on standard definition uses around 1GB of data per hour, while HD requires about 3GB per hour.
  • How many airtime minutes do you need? Most pay monthly phone packages feature unlimited minutes as part of the plan, as do many sim only packages. However, pay as you go sims tend to have a limited number of calls and texts, as well as data caps.
  • What is your budget? Not everything is about money, but if you are on a strict budget then switching to a sim only contract to use on a handset you already own - or one you have purchased or been gifted separately - is sure to reduce your monthly outlay.

Can I Use My Sim Only Deal In Any Handset?

If you have bought a new handset that is not locked to any network then you can insert your new sim and begin to make calls and use data immediately. This sounds drastic, but don’t panic! You can unlock your phone by obtaining a Porting Authorisation Code (PAC) from your supplier. Vodafone actually calls this code a Network Unlock Code (NUC), though it is the same thing as a PAC code, the industry recognised term. You then give the PAC code from your old supplier to your new supplier to complete the switch.

Let’s use a switch from Vodafone and EE as an example. You take out a Vodafone unlimited 5G data deal with an iPhone handset, which runs for 24 months. That handset will be “locked” to Vodafone. At the end of your contract you effectively own the iPhone handset and are now free to switch mobile networks, either for a better deal or because you are unhappy with the service. You shop around for the best sim only packages and decide that the cheap EE sim only deals look perfect, for whatever reason (budget, coverage, perks, etc.). You must now request your PAC code from Vodafone (in Vodafone’s case, NUC). In 2019 Ofcom made it even easier to get your PAC, by introducing a standard PAC retrieval system for every network. Simply text “PAC” to 65075 from your current phone. Your network provider, in this example Vodafone, replies by sending you your PAC code, which will be valid for 30 days. You give that code to EE and they complete the switch, which must be finalised within one working day no matter which network you choose.

All mobile networks operating in the UK have an obligation to help you to switch networks if you are unhappy with their service. However, when you take out a pay monthly phone contract you are bound for the terms of that contract, unless you cancel within your 14 day cooling off period. This could mean that you are contracted to that deal for 12, 24 or even 36 months. If you decide you need to switch networks within the terms of your contract you will face early termination charges, which could be the remainder of your contract term minus the VAT. If you are the kind of person who is likely to get itchy feet with a desire to switch deals when something better comes along, then a sim only rolling monthly phone package is likely the best bet for you.

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