MoneySavingExpert Founder, Martin Lewis · Editor-in-Chief, Marcus Herbert Chair, Martin Lewis · Editor, Marcus Herbert

Top Sim only deals

If you're happy with your phone and out of contract, you could save by switching Sim (the chip in your phone that dictates your data, calls and texts allowance). It's really simple, but do note there's often a credit check. The top deals are below, or click 'Show all deals' to see all deals available.

For full help, see our top Sim-only need-to-knows, including how to keep your number and don't overestimate data use...

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Your top deals

● These are today's prices, but providers often increase prices in line with inflation or a set % during the contract.
● All deals are for new customers. Existing customer? Call your provider to see if it'll offer you it (see haggling help).
Up to 3GB 4GB to 9GB 10GB to 100GB Unlimited data

Up to 3GB Sims - what we'd go for

In our most recent data usage survey, 76% of users told us they only use 3GB/month of data or less. And right now you can get this Lebara Sim, which comes with 3GB/month of data with unlimited minutes and texts, for '£2.46/month' over 12-months, though it's a one-month rolling contract, so you can cancel at any time.


Lebara is also 5G ready and offers Wi-Fi calling if your device is capable. You can also use it to roam in most EU destinations without charge, though it could change its policy on this in the future.

3GB
5G data
UnltdUnltd Minutes
UnltdUnltd Texts
1mthContract
Months 1-6
1p/mth
Thereafter
£4.90/mth
Equiv cost:Equivalent cost: 
£2.46/mth
Lebara Customer service
Uses the Vodafone network
Lebara
Customer service
Uses the Vodafone network
Ends 1 Sep
Get deal*
Via Lebara

4GB to 9GB Sims - what we'd go for

At this data level, our top pick is this 5GB/month Lebara (uses Vodafone's network) deal. Over the year, it's equivalent to £2.96/month – the cheapest 5GB Sim we've seen. It's still a one-month contract, so you can cancel anytime.


Lebara is also 5G ready and offers Wi-Fi calling if your device is capable. You can also use it to roam in most EU destinations without charge, though it could change its policy on this in the future.

5GB
5G data
UnltdUnltd Minutes
UnltdUnltd Texts
1mthContract
Months 1-6
1p/mth
Thereafter
£5.90/mth
Equiv cost:Equivalent cost: 
£2.96/mth
Lebara Customer service
Uses the Vodafone network
Lebara
Customer service
Uses the Vodafone network
Ends 1 Sep
Get deal*
Via Lebara

10GB to 100GB Sims - what we'd go for

Right now there's a bevy of top Sims for data gobblers. Our top pick is this 12GB/month Lebara deal (uses Vodafone's network). It's equivalent to £3.46/month over 12 months – the cheapest 12GB Sim we've ever seen. It's a one-month contract, so you can cancel anytime.


If you don't want to worry about scoffing your allowance, you'll want a virtually unlimited 100GB Sim. Our top pick is this Talkmobile deal (uses Vodafone's network). If you claim the voucher, it's equivalent to £9.87/month over the 12-month contract, or you can get unlimited data for a bit more with the deal below.

12GB
5G data
UnltdUnltd Minutes
UnltdUnltd Texts
1mthContract
Months 1-6
1p/mth
Thereafter
£6.90/mth
Equiv cost:Equivalent cost: 
£3.46/mth
Lebara Customer service
Uses the Vodafone network
Lebara
Customer service
Uses the Vodafone network
Ends 1 Sep
Get deal*
Via Lebara
100GB
5G data
UnltdUnltd Minutes
UnltdUnltd Texts
12mthContract
£25 Amazon voucher
RewardAmazon voucher
Monthly cost
£11.95/mth
Equiv cost:Equivalent cost incl reward: 
£9.87/mth
Talkmobile Customer service
Uses the Vodafone network
Talkmobile
Customer service
Uses the Vodafone network
Ends 8 Sep
Get deal*
Via TalkMobile

Unlimited Sims - what we'd go for

For the data fiends out there, these are our top picks for Sim-only deals with unlimited data allowances, which means you can use as much as you want without having to worry about running out of data.


However, it might be worth looking at the virtually unlimited 100GB/month deals in the table above as they're often cheaper, and is usually enough for even the highest data users.


Do note, some networks limit the download speeds of its unlimited Sims. This is known as throttling. We haven't included Sims that do that here, but it's worth watching out for.

UnltdUnltd
5G data
UnltdUnltd Minutes
UnltdUnltd Texts
12mthContract
£75 Gift card
RewardGift card
Monthly cost
£18/mth
Equiv cost:Equivalent cost incl reward: 
£11.75/mth
iD Mobile Customer service
Uses the Three network
iD Mobile
Customer service
Uses the Three network
Get deal*
Via iD Mobile
UnltdUnltd
5G data
UnltdUnltd Minutes
UnltdUnltd Texts
12mthContract
£40
Automatic cashback
Monthly cost
£16/mth
Equiv cost:Equivalent cost incl cashback: 
£12.67/mth
Three Customer service
Three
Customer service
Get deal*
Via Affordable Mobiles

The top Sim-only need-to-knows

Here are the key points to understand when looking for a Sim-only contract.

Mobile 'text-to-switch' rules make switching and keeping your number far simpler

Switching to a cheaper deal with another network is really easy. Under rules from regulator Ofcom, you no longer have to call your current provider to ditch it, so you avoid the hard sell of it trying to make you stay. Here's how to switch providers and keep your number:

  • Request a switching code by text. Simply text 'PAC' for free to 65075 on any network and you'll be sent your 'porting authorisation code' (PAC) immediately via text so you can keep your number. To get a new number, text 'STAC' to 75075.

Its text must include important info, such as any exit penalties, outstanding handset costs or credit balances.

  • You need to give the switching code to your new provider within 30 days. You'll then be switched within one working day. You won't need to contact your old provider again.

What's more, if you're out of your minimum contract period, mobile providers are now banned from charging you for the remainder of your notice period after you've switched (which is typically 30 days), putting an end to paying for your old and new contract at the same time.

If you're still in contract, you could be charged early termination fees for leaving - check how much you'd be charged by sending a text with the word 'INFO' to 85075.

I've got my PAC, what do I do now?

Though the process varies by provider and you may be able to do it on the phone, once you've got your new (temporary) number from your new network, you'll usually then need to fill in an online form which can be found on the providers site.

The number switch takes place the next working day after you give your PAC to the new provider.

It's a different process if you're swapping within the same provider.

If you're switching to a new tariff on the same network, for example if you're on pay-as-you-go and upgrading to a contract, you shouldn't need to carry out this process - just call your mobile provider's customer service helpline and they should be able to sort it.

It's important to remember that the Sim-only deals listed in our Cheap Mobile Finder are mostly for newbies of that provider. If you apply for a deal that's with your current provider and attempt to switch your current number to it, it'll likely be rejected by your network.

Don't overestimate how much data you need - most use less than 3GB a month

If you don't get close to using your allowance of minutes, data and texts each month, you're essentially overpaying for your contract. Bust your limit though, and the extra charges can be costly.

In our last MSE data usage poll, 76% of the 4,500 respondents said they use less than 3GB a month, while only 8% of people actually use more than 10GB a month.

If you want to check your usage, our handy Data Calculator can help you. Key in your usage (for when you're not using Wi-Fi) and it'll give you a general idea of how much data you need.

You'll need an unlocked phone - it's usually free to get it done

If you bought your phone on a traditional contract, it may be locked to the network that sold it to you (to check, pop in another network's Sim and see if it works). If you find it's locked, you'll usually need to unlock it so your new provider's Sim will work.

If you're out of contract, your network must do this for free. If still in contract or you bought it on pay-as-you-go, you may be charged around £10 to unlock it - see our Mobile unlocking guide for a full list of providers' unlocking policies and how to do it.

New rules brought in from December 2021 mean mobile companies are banned from selling 'locked' phones, which only work with their network. This means people who buy a phone now are able to switch networks using their existing handset, without unlocking it.

Check signal strength where you live/work first

You can get an idea of signal strength in a particular area with Ofcom's Telecoms Coverage Checker. This will show you results for four main networks - EE, O2, Three and Vodafone - but 'piggyback' networks use their signal too, and generally offer far better value, so don't think your options are limited to one of the biggies. However, some of these networks don't offer services such as wifi-calling, so check if this is important to you. See a full list of which provider is on which network in our Mobile piggybacking guide.

Alternatively, to check with the provider directly, you can use the 'check network coverage' links in our Cheap Mobile Finder tool.

If you have a 5G handset, and want to take advantage of 5G speeds with your Sim, check out our 5G guide for more info on where you can get 5G. It's worth bearing in mind that some piggybackers, such as Smarty and iD Mobile, don't yet support 5G so it's worth checking first if the Sim is also 5G capable.

If you can only get 3G/4G where you live/work, the quality of the signal you'll receive will depend on where you are. Across all the networks, big cities and towns should have a decent 4G signal - while those in rural areas can struggle to get even 3G.

If you have the time (and patience), for a more accurate indication of a providers signal in your area, you could get a free pay-as-you-go Sim from the network you're considering, topping it up with a bit of credit and putting it to the test before committing.

Happy with your provider? Try haggling for a better deal

Haggling on monthly mobile phone contracts can slash the price you pay. If you have a contract deal and you're nearing the end of your fixed term, your network will be frantically trying to keep you, so it's the best time to haggle. Long-term customers have a better chance of success here.

Our latest poll showed the best mobile providers to haggle with are Sky Mobile and Three. See our Mobile phone haggling guide for help with getting a better deal. Bear in mind though it's usually harder to haggle on a contract for a new phone, particularly if you're after the latest model.

Before you call your provider, arm yourself with 'new customer' deals

All of the deals in our Cheap Mobile Finder are for new customers of that provider, but you could use the deals listed in our tool to try and haggle yourself a better one with your current provider.

Prices can rise with inflation each year

Mobile networks are permitted to increase your monthly tariff price each year, but only if their T&Cs state so before you sign up. And all the major networks have such terms, including EE, O2, Three, Virgin Mobile and Vodafone.

Changes are usually made in line with the Retail Prices Index (RPI, a measure of inflation) between February and April each year, but recently, some firms have chosen to change the way their prices rise each year, opting to increase by inflation, plus a percentage amount on top.

If a provider hikes your monthly bill and its T&Cs don't allow this - then you can leave your contract penalty-free.

You could make extra savings with some cashback deals - though be warned...

It's possible to nab extra savings through cashback on some deals. There are three types of cashback available, and they all work differently:

  1. Redemption cashback. The biggest discounts are on 'cashback redemption' deals through mobile reseller sites. These require you to send off your bills at several points throughout your contract and get paid in instalments - miss one and you'll lose out.
  2. Automatic cashback. These deals, also via resellers, are where you're sent a cheque automatically within a few months without having to claim, though usually they don't offer as big a discount. Some deals can also offer part manual, part automatic cashback.
  3. Cashback via cashback sites. It's possible sometimes to beat the deals in our Cheap Mobile Finder with some offers via dedicated cashback websites. However, don't think of this type of cashback as guaranteed - there are often problems. Read our Top cashback sites guide for full info.

Key things to watch out for when taking out a new Sim-only contract, including credit checks

If you're willing to commit to a Sim-only contract, there are a couple of final things you need to be aware of...

You'll be credit-checked

If you choose to opt for a pay-monthly Sim, most providers will carry out a credit check, so if you tend to struggle getting credit, you may want to check your credit score before applying.

MoneySavingExpert.com's free Credit Club gives you your free Experian credit score and credit report. While it won't tell you for definite whether you'll pass a credit check for a contract, it will give you a general idea of whether you'll be seen as a good or bad credit risk.

If you think you're unlikely to pass a credit check, or tried and were declined, it could be better to opt for a 30-day rolling Sim (check for providers that don't do credit checks on these Sims), or a pay-as-you-go Sim instead.

Deals are usually for new customers only

The deals here and on most comparison sites are geared towards new customers of the relevant network.

If you're already with that network, even if your existing contract is up and you try to get the deal, you'll have trouble porting (in other words, moving) your current phone number to your new plan. Of course, you can still get the deal if you take out a separate new contract. But if you do, you may be left with a new phone number.

There is a way around this, though it's a bit of work. You can get the deal on a separate new contract, and also get yourself a free pay-as-you-go Sim from a different network.

Port (move) your existing number across to the free pay-as-you-go Sim, then port it again to the new contract once it's been set up. To port your number over, you'll need to request a porting authorisation code from your provider.

How to complain about your network

The mobile industry doesn't have the best customer service reputation and while a provider may be good for some, it can be hell for others. Common problems include limited network coverage, slow data speeds, unexpected charges and more.

It's always worth trying to call your provider to sort the issue first, but if not then you can use free complaints tool Resolver. The tool helps you manage your complaint, and if the company doesn't play ball, it also helps you escalate your complaint to the free Ombudsman (or CISAS if you're complaining about Virgin Mobile or Sky Mobile).

FAQs

Why choose a Sim only deal?

A Sim only deal is good if you're happy with your phone, or want to buy a new one without having to sign up to a long contract. See all cheap Sim deals in our Cheap Mobile Finder tool.

Who are the main networks in the UK?

There are four main networks in the UK: Vodafone, Three, EE and O2. You can use our Cheap Mobile Finder to filter networks if you know a certain network has better coverage in your area.

There are also smaller networks which piggyback of the main networks. These are known as mobile virtual network operators (MVNO's). These are separate from the big providers, but have agreements in place to use their networks, so this can be a good way to save if only one network has good coverage where you are. An example would be GiffGaff which uses O2's network to operate its service. More examples include Voxi (uses Vodafone), Tesco Mobile (uses O2), Virgin Mobile (uses Vodafone) and Smarty (uses Three).

What are the different types of Sim cards?

There are three main types and sizes of Sim card available, which fit specific devices. These are:

  • Standard Sim card (15mm x 25mm)
  • Micro Sim card (12mm x 15mm)
  • Nano Sim card (8.8m x 12.3mm)

When you order a Sim card from a provider, it'll usually send a 3-in-1 Sim, so if your phone supports a smaller size, you'll be able to break it down to the correct size for your phone. The latest smartphones will usually work with a nano Sim.

How much data should I look for in a Sim only deal?

In our last MSE data usage poll, 76% of the 4,500 respondents said they use less than 3GB a month, while only 8% of people actually use more than 10GB a month.

If you want to check your usage, our handy Data Calculator in our Cheap Mobile Finder tool can help you. Key in your usage (for when you're not using Wi-Fi) and it'll give you a general idea of how much data you need.

How easy is it to switch networks?

Switching to a cheaper deal with another network is easy. Here's how to switch providers and keep your number:

  • Request a switching code by text. Simply text 'PAC' for free to 65075 on any network and you'll be sent your 'porting authorisation code' (PAC) immediately via text so you can keep your number. To get a new number, text 'STAC' to 75075.

Its text must include important info, such as any exit penalties, outstanding handset costs or credit balances.

  • You need to give the switching code to your new provider within 30 days. You'll then be switched within one working day. You won't need to contact your old provider again.