SIM only Comparison

SIM only comparison

Keep your phone, upgrade your value.

Why pay for a handset you already own? Wisemium analyzes the market to find SIM-only plans that offer more data for less spend. We simplify the fine print so you can switch with confidence.

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Compare Deals From UK's Biggest Networks

Compare SIM-Only Deals

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Network Name	Data Allowance	Calls/Texts	Contract Type	Monthly Cost (Est.)	Action
Smarty	IOOGB (5G)	Unlimited	1 Month (Rolling)	£10.00	View Deal
Voxi	Unlimited Social	Unlimited	1 Month (Rolling)	£12.00	View Deal
Lebara	30GB + Free Roaming	Unlimited	1 Month (Rolling)	£8.00	View Deal
Three	Unlimited Data	Unlimited	24 Months	£22.00	View Deal
O2	50GB + Priority	Unlimited	12 Months	£18.00	View Deal
Lyca Mobile	60GB (5G)	Unlimited	I Month (Rolling)	£12.00	View Deal

Understanding the SIM-Only Advantage

Traditional mobile contracts often hide the true cost of a device within your monthly bill. A SIM-only plan strips away those hidden hardware costs, focusing entirely on what you actually use: your data, minutes, and texts.

With a SIM only deal, you need to provide the device. That means using a phone you’ve already got or buying a new one.

Understanding Your SIM Card

Modern mobile technology uses three primary formats: Standard, Micro, and Nano. To make things simple, Wisemium provides “Multi-SIMs”—a clever 3-in-1 design that allows you to pop out the exact size your specific device requires

SIM cards come in different sizes: Standard, Micro and Nano. Once you’ve chosen your SIM-card deal, you’ll probably receive a Multi or Combi SIM, which gives you a choice of all three sizes. You pick the one that fits your mobile phone.

Your SIM is highly portable and can be moved between any compatible devices. To use your new SIM, your phone must be unlocked (not restricted to a specific carrier). To test this, simply insert the card; if you see network bars and can place a call, your device is ready. If not, your previous provider can typically unlock the handset for you.

Understanding eSIM Technology

A SIM-only deal allows you to pay exclusively for your network services—data, minutes, and texts—without the added monthly expense of a handset loan. Transitioning from a standard mobile contract to a SIM-only plan typically results in a significant reduction of your monthly bill. However, keep in mind that you must provide your own device, either by using your current phone or purchasing one separately.

Instead of inserting a plastic card, you activate an eSIM digitally by scanning a QR code or using a dedicated provider app. This digital transition is growing rapidly; global mobile associations project that over a third of all smartphones will rely on eSIM technology by 2026.

The Advantage: eSIMs generally cost the same as traditional SIMs and are supported by major UK networks including EE, Vodafone, O2, Three, and Lyca Mobile.

The Trade-off: Transferring an eSIM to a new device is slightly more involved than swapping a physical card, as it requires a fresh digital activation process on the new hardware.

eSIM technology is featured in most modern handsets released over the last decade. To use this service, you will need a compatible device, such as:

You’ll need a newer iPhone or Android phone, such as:

Apple: iPhone XR, XS, and all subsequent models.

Google: Pixel 2 and all newer generations.

Samsung: Galaxy S20 series and all later flagships.

Sony: Xperia 1 IV, 10 IV, 1 MK5, and 10 MK5.

Others: Recent premium models from Motorola, Huawei, Oppo, and Rakuten.

How SIM-Only Plans Function

Available SIM-Only Options in the UK

Long-Term Contracts (12 & 24 Months): These plans offer a fixed monthly allowance for data, calls, and texts. You are billed monthly, removing the need for manual credit top-ups.
Flexible Rolling Monthly Plans: These 30-day contracts renew every month and offer the freedom to switch or cancel your plan with just one month’s notice.
No-Contract Pay As You Go (PAYG): Ideal for light users, this option requires you to add credit to your SIM and pay only for the exact amount of data, minutes, and messages you consume.
Data-Only Solutions: These plans focus entirely on internet connectivity. While they do not traditionally include a standard phone number for cellular calls, they are perfect for tablets or users who rely solely on data-based communication apps.

What happens when I choose a SIM only deal?

Once you’ve chosen your SIM only deal from our price comparison, you can sign up online too.

Click the ‘Buy now’ button. You’ll get an overview of the deal. If you’re happy, click ‘Continue’ to go straight to the provider’s website.
Sign up. Share your details and accept the terms of the contract or pay-as-you-go plan.
Get your PAC (Porting Authorisation Code). This allows you to keep the same mobile number. To start the process, text PAC to 65075. Your provider will reply with the code or the next steps to get it. You can also request it via your online account on your provider’s website. Your PAC is valid for 30 days.
Get your SIM card. Choose the right size for your mobile, slot it in and you’re ready to go.

Can I move to a SIM only deal with my current network provider?

If you’re out of contract, it’s usually easy to switch to a new and cheaper SIM only deal with any provider – and keep your number.

If you’ll be ending your contract early, you’ll probably need to pay off the rest of the money you owe in a lump sum. Depending on the amount, it might make sense to wait until your contract ends before you kick-start a new SIM only plan.

What are the advantages of a SIM only deal?

SIM only deals come with shorter contracts, from 30 days upwards, as well as Pay As You Go plans which are contract free.

You don’t have to make a long-term commitment and it’s quick and easy to switch to a new plan if a better offer comes along or your needs change. Your network provider may still want a month’s notice though.

You can pay for what you need

With SIM only contracts, customisable plans let you choose the number of minutes and texts and amount of data that works for you, including unlimited data. Some plans also come with EU roaming, so you can use your phone abroad. Or you can get plans with unlimited use of social apps and access to services such as Netflix or Prime Video that won’t count as part of your data usage.

You may also have 5G and Wi-Fi calling if your phone is compatible.

It’s easier to change providers

With a SIM only deal, you’re not locked into a particular network. If you’re not happy with your current network provider and you’re not tied into a 12-or 24-month contract, you can easily switch to another.

Upgrading your phone is easy

Want the latest handset? You don’t need to wait. As long as it’s compatible with your SIM, you can upgrade and your monthly payments won’t change.

You can keep your phone

You’ve set up all the apps, you like the way it works: if you don’t want to upgrade, a SIM only deal allows you to hang on to your existing model.

No credit check

If you’re worried about your credit rating or you’ve been turned down for a mobile contract elsewhere, many providers offer SIM only plans, no credit check required. They may need to do an ID check though.

If your credit rating isn’t looking good, a SIM only contract can improve it over time provided you don’t miss any payments.

What are the disadvantages of SIM only deals?

Here are a few of the potential SIM only downsides.

The upfront cost of buying a phone

If you don’t have a handset, you’ll need to buy one. If you love the latest tech, this could be an expensive business. You can pick up a budget smartphone for around £100. Top-of-the-range models are much more.

Your device might become obsolete

A series of SIM only deals increases the likelihood that your phone will date, stop working effectively and even put your data at risk.

You might need to unlock your phone

It’s been illegal for network providers to lock your phone since December 2021, but if you got your phone before then, it might need to be unlocked. This can be a complicated process and comes with a fee.

What are the advantages of an eSIM?

Because you download an eSIM using an app or QR code, you can be up and running in minutes rather than having to wait for a SIM to be delivered.

Even better, because you can have multiple eSIM profiles on your device, you can choose the one with the best network coverage for where you are or the lowest roaming charges if you’re travelling abroad.

How to get the best SIM only deals

The best SIM only deal for you isn’t just about price. It’ll be the one that ticks all your boxes for flexibility and what’s included in the package too.

An online comparison service can flag up the best SIM only deals that also match your specific criteria. Here are a few questions to help you decide on the best SIM card only deal for you. On a monthly basis:

How much data do you use?
How many minutes do you need?
How many texts do you usually send?
What kind of download speeds are you looking for?
Do you want a pay-as-you-go SIM or a 30-day, 12-month or 24-month contract? A longer-term contract is likely to be cheaper, but a monthly SIM gives you more flexibility to switch to different network providers or tariffs.
Do you travel a lot – and if so, where do you go? EU roaming and beyond is often included.

If you’re not sure about your average monthly usage, you can look at your mobile phone bills.

Look out for the freebies and extra perks that often come with mobile SIM only deals too. These include priority gig tickets and free music downloads, as well as broadband deals and 5G at no extra cost. Just make sure your smartphone is 5G enabled and you’ve got coverage in your area.

To see if you can get 5G where you live, put your postcode into Ofcom’s coverage checker.

How much data should I get with my SIM only deal?

Pick a data allowance that matches your monthly usage. It’s important to avoid overpaying, but on the other hand, exceeding your data allowance can be expensive.

Your phone’s settings will show you how much data you’re getting through. To get an overview of what you use month by month, log into your mobile account.

In 2022, according to Ofcom, the average user consumed 5.6GB of mobile data a month.

Over 70% of customers on a SIM only plan have been overpaying for data they didn’t use according to Citizens Advice. That’s a total cost of £800 million a year. And it amounts to an average of 2GB of wastage a month.

What download speeds should I be looking for with a SIM only deal?

Many SIM only deals now include 5G, for minimum data speeds of around 50Mbps (megabytes per second). Make sure you check whether 5G is available in your area before you commit to a plan.

If you don’t have access to 5G, a 4G SIM only deal is the next best option. 3G is now on its way out. EE, Vodafone, Three and O2 began their switch-off in early 2023 and are planning to gradually retire their 3G networks over the next few years. If you’ve got an older handset, this may affect you. Your provider will tell you if this is likely. If so, you might be able to get 4G on your phone. If not, you’ll need to replace it.

The faster your data speed, the more you can do. Top speeds make things like live streaming and multiplayer online games almost effortless. For simple tasks like streaming or downloading music, sending texts and browsing online, 2Mbps is usually fast enough.

Which SIM only deals include data roaming?

Data roaming allows you to use data abroad. Some SIM only deals include roaming in certain countries in the EU and beyond.

You can get SIM only deals with EU roaming included from iD Mobile, Lebara, Lyca Mobile, O2, SMARTY, and Talkmobile.

This means most calls, texts and data usage are charged at the same rate you’d pay at home and come out of your usual allowance. But always check the details of the deal and what countries it covers.

You may also have the option to buy a data bundle for the country you’re going to.

For SIM only deals on a rolling monthly contract, you can plan ahead and change your allowance if you’re going to be away for longer.

If you’re on a 12- or 24-month SIM only contract which doesn’t include a good deal on data roaming, getting a temporary physical SIM may be your next best option. Alternatively, you can upload an eSIM if it’s compatible with your smartphone.

This allows you to access data roaming offers from other providers which may be cheaper than what you usually get. The downside is that you’ll have a different mobile number while you’re away.

If you’re a regular traveller – although you still spend most of your time in the UK – it pays to compare offers for the best-value SIM only deal with the roaming add-on you need.

How does cashback work on SIM only deals?

Getting cashback from your SIM only deal means that you get back some of the money you’ve spent, whether that’s with a mobile phone retailer or a network provider.

Cashback on your SIM only deal usually works in one of two ways:

Automatic cashback – your money is paid back automatically into your bank account, 30+ days after you connect to the mobile network using your SIM.
Cashback by redemption requires more effort on your part. You get the money back in equal instalments on set dates during your contract. This involves knowing which months to make a claim and then uploading your bill online to receive the money. It helps to set yourself reminders so you don’t miss the deadlines.

You may also have the option to make your claim by recorded post. If you take that route, make sure you keep proof of postage for reference.

Who has the best SIM only deals?

The best SIM only deal depends on what you’re looking for.

There are four major mobile providers in the UK: EE, Vodafone, Three and O2. They have plenty of competitive plans, with a choice of text, minutes and data allowances, plus perks and freebies.

It’s also worth looking at SIM only deals from the mobile virtual network operators (MVNOs). They don’t own or operate their own networks. Instead, they’re hosted by one of the big four.

These virtual networks don’t have the overheads of their parent companies and can provide cost-effective SIM only deals. They include giffgaff, Tesco Mobile, iD Mobile and Lebara.

They offer SIM only plans for both light and heavy smartphone users, along with plenty of incentives.

If you can wait, sales such as November’s Black Friday can also be great opportunities to pick up a cheap SIM only deal.

Which SIM only deals use the EE network?

EE has been named the top UK network for overall performance for the tenth year running. It’s also the parent company to three major MNVOs: Lyca Mobile, BT Mobile and Plusnet Mobile, as well as a host of smaller brands which offer competitive SIM only deals.

You won’t find EE SIM only deals on price comparison websites. That stopped in March 2023. But there are plenty of offers available from the brands it hosts. You get the same great coverage and maybe even access to extras and benefits that the main network doesn’t offer.

Unsure how much monthly data you need?

Our mobile data usage calculator can help. From 100MB to 10GB, find out how far your data package will get you.