SIM-only deals can save you money on your mobile phone bill every month. Compare the UK’s best value SIM-only deals.

A good way to save money on your phone bill is by switching to a SIM-only deal. This is a low-cost SIM card for your mobile phone with an inclusive allowance of minutes, texts and mobile data. You can keep your current phone number when changing to a SIM-only deal and will normally get lots of flexibility with either a 12-month or a 1-month rolling contract.

In this article, we’ll review and compare the UK’s best value SIM-only deals. This includes big name mobile networks like EE, O2, Three and Vodafone as well as lower-cost alternatives like giffgaff, iD Mobile, SMARTY and VOXI.

How Do SIM Only Deals Work?

A SIM only deal for your mobile phone gives you an allowance of minutes, texts and mobile data. You’ll get a new SIM card that slots into your smartphone, normally with much lower prices than what you’d pay on a normal mobile contract.

Here are some key things to know about SIM Only deals:

1. You’ll Keep Your Existing Phone Number

When switching to a SIM-only deal, it’s easy taking your phone number with you. Simply request a PAC Code from your old mobile network, either through their app, website or text message. You can then provide this code to your new network. Our PAC Code Finder can walk you through this process one step at a time.

2. The New SIM Card Slots Into Your Smartphone

When you sign up for a SIM-only deal, you’ll be sent a SIM card through the post from your new mobile network. This SIM card will slot inside your current smartphone. There’s no need to backup or to transfer any data: your phone book, photos, messages and other apps will still be there after you change your SIM card.

If your mobile phone was previously used on another mobile network, it might be necessary for you to unlock it. For more information, see our step-by-step guides to unlocking an iPhone and unlocking a Samsung Galaxy smartphone.

3. You’ll Always Get Coverage From EE, O2, Three or Vodafone

Regardless of which mobile network you choose, you’ll always be getting coverage from one of the four big providers.

Other mobile networks piggyback on coverage from the big four:

4. You’ll Save Money Compared To A Regular Contract

A SIM-only deal will usually work out to be much cheaper than a traditional 24-month contract. For instance, you might need to pay around £50/month for the latest iPhone on a 24-month contract with 4GB of data. The equivalent SIM-only deal would cost you around £8/month, saving you in the region of £500 per year.

Nowadays, many people decide to buy their mobile phones on a SIM-free basis and use it in conjunction with a SIM-only deal. This usually saves you a fair bit of money and gives you a lot more flexibility compared to a 24-month contract.

Compare SIM Only Deals

The following interactive comparison tool can help you to find the best value SIM card for your usage.

Simply choose how much data you want on your SIM-only deal, the maximum contract length you’d be happy with and the mobile networks you’re considering:

How much data do you want on your plan each month?

How long are you willing to commit for on a contract?

Which networks would you be happy to take a plan from?

Showing 179 of 179 price plans that match your criteria

NetworkMinutesTextsDataMonthly
Cost
Lebara Mobile1,0001,0002GB£5.00
1 month
TalkmobileUnlimitedUnlimited1GB£5.00
1 month
iD MobileUnlimitedUnlimited1GB£5.00
1 month
ThreeUnlimitedUnlimited1GB£5.00
12 months
ThreeUnlimitedUnlimited1GB£5.00
24 months
Three600Unlimited1GB£5.00
12 months
ASDA Mobile200Unlimited750MB£5.00
1 month
ThreeUnlimitedUnlimited4GB£6.00
12 months
iD MobileUnlimitedUnlimited4GB£6.00
1 month
Virgin MobileUnlimitedUnlimited3GB£6.00
12 months
Plusnet MobileUnlimitedUnlimited3GB£6.00
1 month
Sky MobileUnlimitedUnlimited2GB£6.00
12 months
VodafoneUnlimitedUnlimited2GB£6.00
12 months
SmartyUnlimitedUnlimited1GB£6.00
1 month
giffgaffUnlimitedUnlimited500MB£6.00
1 month
iD MobileUnlimitedUnlimited6GB£7.00
1 month
TalkmobileUnlimitedUnlimited3GB£7.00
1 month
TalkmobileUnlimitedUnlimited3GB£7.00
12 months
ASDA Mobile300Unlimited2.5GB£7.00
1 month
SmartyUnlimitedUnlimited2GB£7.00
1 month
Virgin MobileUnlimitedUnlimited1GB£7.00
12 months
Tesco Mobile5005,0002GB£7.50
12 months
ThreeUnlimitedUnlimited12GB£8.00
12 months
iD MobileUnlimitedUnlimited12GB£8.00
1 month
O2UnlimitedUnlimited10GB£8.00
12 months
ThreeUnlimitedUnlimited8GB£8.00
12 months
VodafoneUnlimitedUnlimited8GB£8.00
12 months
Virgin MobileUnlimitedUnlimited8GB£8.00
12 months
Plusnet MobileUnlimitedUnlimited7GB£8.00
1 month
SmartyUnlimitedUnlimited3GB£8.00
1 month
Virgin MobileUnlimitedUnlimited3GB£8.00
24 months
Sky MobileUnlimitedUnlimited3GB£8.00
12 months
giffgaffUnlimitedUnlimited2GB£8.00
1 month
TalkmobileUnlimitedUnlimited9GB£9.00
12 months
ThreeUnlimitedUnlimited8GB£9.00
24 months
SmartyUnlimitedUnlimited4GB£9.00
1 month
ThreeUnlimitedUnlimited4GB£9.00
12 months
ThreeUnlimitedUnlimited4GB£9.00
24 months
Virgin MobileUnlimitedUnlimited2GB£9.00
12 months
SmartyUnlimitedUnlimited30GB£10.00
1 month
VodafoneUnlimitedUnlimited12GB£10.00
12 months
ThreeUnlimitedUnlimited12GB£10.00
12 months
ThreeUnlimitedUnlimited12GB£10.00
24 months
Tesco Mobile5,0005,00012GB£10.00
18 months
Lebara MobileUnlimitedUnlimited10GB£10.00
1 month
Plusnet MobileUnlimitedUnlimited10GB£10.00
1 month
giffgaffUnlimitedUnlimited9GB£10.00
1 month
ThreeUnlimitedUnlimited8GB£10.00
12 months
Tesco Mobile5,0005,0008GB£10.00
12 months
ASDA Mobile600Unlimited7GB£10.00
1 month
giffgaffUnlimitedUnlimited6GB£10.00
1 month
VOXIUnlimitedUnlimited6GB£10.00
1 month
Lebara MobileUnlimitedUnlimited6GB£10.00
1 month
TalkmobileUnlimitedUnlimited6GB£10.00
1 month
Superdrug MobileUnlimitedUnlimited5GB£10.00
1 month
O2UnlimitedUnlimited5GB£10.00
18 months
Virgin MobileUnlimitedUnlimited5GB£10.00
24 months
Virgin MobileUnlimitedUnlimited4GB£10.00
12 months
BT MobileUnlimitedUnlimited1GB£10.00
24 months
VodafoneUnlimitedUnlimited1GB£11.00
24 months
SmartyUnlimitedUnlimited50GB£12.00
1 month
Virgin MobileUnlimitedUnlimited32GB£12.00
24 months
ThreeUnlimitedUnlimited30GB£12.00
12 months
iD MobileUnlimitedUnlimited30GB£12.00
1 month
Virgin MobileUnlimitedUnlimited25GB£12.00
12 months
TalkmobileUnlimitedUnlimited15GB£12.00
12 months
ThreeUnlimitedUnlimited12GB£12.00
12 months
VOXIUnlimitedUnlimited12GB£12.00
1 month
giffgaffUnlimitedUnlimited10GB£12.00
1 month
O2UnlimitedUnlimited10GB£12.00
18 months
Sky MobileUnlimitedUnlimited10GB£12.00
12 months
O2UnlimitedUnlimited2GB£12.00
12 months
BT MobileUnlimitedUnlimited2GB£12.00
12 months
VodafoneUnlimitedUnlimited1GB£12.00
12 months
Tesco Mobile5,0005,00020GB£12.50
18 months
Tesco Mobile5,0005,00015GB£12.50
12 months
iD MobileUnlimitedUnlimited50GB£13.00
1 month
Virgin MobileUnlimitedUnlimited6GB£13.00
12 months
ThreeUnlimitedUnlimited30GB£14.00
24 months
Virgin MobileUnlimitedUnlimited10GB£14.00
24 months
Virgin MobileUnlimitedUnlimited8GB£14.00
12 months
BT MobileUnlimitedUnlimited5GB£14.00
12 months
TalkmobileUnlimitedUnlimited50GB£15.00
12 months
VodafoneUnlimitedUnlimited30GB£15.00
12 months
ThreeUnlimitedUnlimited30GB£15.00
12 months
O2UnlimitedUnlimited30GB£15.00
18 months
Tesco Mobile5,0005,00030GB£15.00
18 months
Tesco Mobile5,0005,00025GB£15.00
12 months
giffgaffUnlimitedUnlimited15GB£15.00
1 month
VOXIUnlimitedUnlimited15GB£15.00
1 month
Superdrug MobileUnlimitedUnlimited15GB£15.00
1 month
Sky MobileUnlimitedUnlimited15GB£15.00
12 months
Lebara MobileUnlimitedUnlimited10GB£15.00
1 month
Virgin MobileUnlimitedUnlimited10GB£15.00
12 months
BT MobileUnlimitedUnlimited10GB£15.00
24 months
ASDA Mobile1,000Unlimited10GB£15.00
1 month
Tesco Mobile5,0005,0006GB£15.00
12 months
VodafoneUnlimitedUnlimited5GB£15.00
24 months
O2UnlimitedUnlimited5GB£15.00
12 months
ThreeUnlimitedUnlimitedUnlimited£16.00
12 months
Virgin MobileUnlimitedUnlimited50GB£16.00
12 months
Virgin Mobile2,500Unlimited20GB£16.00
24 months
VodafoneUnlimitedUnlimited5GB£16.00
12 months
ThreeUnlimitedUnlimited4GB£16.00
1 month
EEUnlimitedUnlimited1GB£16.00
12 months
ThreeUnlimitedUnlimitedUnlimited£17.00
12 months
ThreeUnlimitedUnlimitedUnlimited£17.00
24 months
BT MobileUnlimitedUnlimited12GB£17.00
12 months
O2UnlimitedUnlimited10GB£17.00
12 months
SmartyUnlimitedUnlimitedUnlimited£18.00
1 month
ThreeUnlimitedUnlimitedUnlimited£18.00
12 months
O2UnlimitedUnlimited60GB£18.00
18 months
Virgin MobileUnlimitedUnlimited30GB£18.00
24 months
Virgin MobileUnlimitedUnlimited20GB£18.00
12 months
Superdrug MobileUnlimitedUnlimited20GB£18.00
1 month
ThreeUnlimitedUnlimited12GB£19.00
1 month
EEUnlimitedUnlimited3GB£19.00
12 months
Superdrug MobileUnlimitedUnlimitedUnlimited£20.00
1 month
EEUnlimitedUnlimited160GB£20.00
24 months
O2UnlimitedUnlimited120GB£20.00
12 months
Virgin MobileUnlimitedUnlimited100GB£20.00
24 months
TalkmobileUnlimitedUnlimited100GB£20.00
12 months
VodafoneUnlimitedUnlimited100GB£20.00
12 months
EEUnlimitedUnlimited100GB£20.00
24 months
giffgaffUnlimitedUnlimited80GB£20.00
1 month
VodafoneUnlimitedUnlimited60GB£20.00
24 months
VOXIUnlimitedUnlimited45GB£20.00
1 month
Virgin MobileUnlimitedUnlimited25GB£20.00
12 months
BT MobileUnlimitedUnlimited25GB£20.00
24 months
Tesco Mobile5,0005,00025GB£20.00
12 months
Lebara MobileUnlimitedUnlimited20GB£20.00
1 month
ASDA MobileUnlimitedUnlimited12GB£20.00
1 month
VodafoneUnlimitedUnlimited1GB£20.00
1 month
BT MobileUnlimitedUnlimited30GB£21.00
12 months
VodafoneUnlimitedUnlimited20GB£21.00
12 months
VodafoneUnlimitedUnlimitedUnlimited£22.00
24 months
ThreeUnlimitedUnlimitedUnlimited£22.00
24 months
Virgin MobileUnlimitedUnlimited50GB£22.00
12 months
EEUnlimitedUnlimited20GB£22.00
12 months
EEUnlimitedUnlimited200GB£23.00
24 months
ThreeUnlimitedUnlimitedUnlimited£24.00
1 month
VodafoneUnlimitedUnlimitedUnlimited£24.00
12 months
ThreeUnlimitedUnlimitedUnlimited£24.00
12 months
ThreeUnlimitedUnlimited30GB£24.00
1 month
VodafoneUnlimitedUnlimited5GB£24.00
1 month
giffgaffUnlimitedUnlimitedAlways-On£25.00
1 month
O2UnlimitedUnlimited250GB£25.00
12 months
EEUnlimitedUnlimited200GB£25.00
24 months
O2UnlimitedUnlimited150GB£25.00
12 months
Virgin MobileUnlimitedUnlimited100GB£25.00
12 months
BT MobileUnlimitedUnlimited100GB£25.00
24 months
EEUnlimitedUnlimited40GB£25.00
12 months
VodafoneUnlimitedUnlimited40GB£25.00
24 months
Sky MobileUnlimitedUnlimited25GB£25.00
12 months
ASDA MobileUnlimitedUnlimited15GB£25.00
1 month
ThreeUnlimitedUnlimitedUnlimited£26.00
1 month
VodafoneUnlimitedUnlimitedUnlimited£26.00
24 months
Virgin MobileUnlimitedUnlimitedUnlimited£27.00
24 months
VodafoneUnlimitedUnlimited40GB£27.00
12 months
VodafoneUnlimitedUnlimitedUnlimited£28.00
12 months
Tesco Mobile5,0005,000Unlimited£28.00
18 months
EEUnlimitedUnlimited100GB£29.00
24 months
VodafoneUnlimitedUnlimited20GB£29.00
1 month
Virgin MobileUnlimitedUnlimitedUnlimited£30.00
12 months
VodafoneUnlimitedUnlimitedUnlimited£30.00
24 months
Tesco Mobile5,0005,000Unlimited£30.00
12 months
Tesco Mobile5,0005,000Unlimited£30.00
12 months
BT MobileUnlimitedUnlimited100GB£30.00
12 months
VodafoneUnlimitedUnlimitedUnlimited£32.00
1 month
VodafoneUnlimitedUnlimitedUnlimited£33.00
12 months
O2UnlimitedUnlimitedUnlimited£33.00
18 months
O2UnlimitedUnlimitedUnlimited£35.00
12 months
VOXIUnlimitedUnlimitedUnlimited£35.00
1 month
Lebara MobileUnlimitedUnlimitedUnlimited£35.00
1 month
giffgaffUnlimitedUnlimitedUnlimited£35.00
1 month
VodafoneUnlimitedUnlimitedUnlimited£36.00
1 month
EEUnlimitedUnlimitedUnlimited£37.00
24 months
VodafoneUnlimitedUnlimitedUnlimited£41.00
1 month
EEUnlimitedUnlimitedUnlimited£41.00
24 months

You can scroll through the full list of price plans to see currently available deals that match your criteria. If you’re not sure about how much data you’d like on your plan, see our guide to mobile download limits.

Best SIM Only Networks By Feature

Best SIM Card For Value

The best value SIM-only deal really depends on how much data you need each month. It’s important not to get carried away and to choose a plan with lots more data than you actually need.

Once you’ve decided how much data you need, the following table will show you a summary of the cheapest SIM-only mobile networks with at least that amount of data:

Data AllowanceCheapest PlanCheapest Mobile Network
500MB Data£5.00/monthLebara Mobile & Talkmobile
1GB Data£5.00/monthLebara Mobile & Talkmobile
2GB Data£5.00/monthLebara Mobile
3GB Data£6.00/monthThree & iD Mobile
4GB Data£6.00/monthThree & iD Mobile
6GB Data£7.00/monthiD Mobile
8GB Data£8.00/monthThree & iD Mobile
12GB Data£8.00/monthThree & iD Mobile
20GB Data£10.00/monthSmarty
100GB Data£16.00/monthThree

Alternatively, use the interactive comparison table above, selecting the amount of data you need. It will show you a list of available price plans that match your criteria.

Best SIM Card For Network Coverage

If you’re looking for the SIM-only mobile network that gives you the best coverage, there isn’t a simple answer to this as it depends very much on where you live.

All four network coverage providers claim to offer 99% population coverage, but they differ in the exact areas they cover and in the strength and type of mobile signal.

The easiest way to check the coverage in your area is by clicking through to the relevant online coverage maps for each provider:

Enter your postcode on each of the above coverage maps to see whether you’re able to get coverage where you live. Alternatively, you can read our in-depth guides to the coverage on EE, O2, Three and Vodafone.

Once you’ve figured out the coverage providers that work in your area, find out which mobile networks piggyback on each provider. Piggyback mobile networks offer the same underlying coverage as the host mobile network provider.

Our interactive comparison table above will allow you to filter SIM-only deals by the coverage provider they’re using.

Best SIM Card For Flexibility & No Credit Check

If you’re looking for a flexible SIM card that doesn’t require credit checks, you can choose a SIM-only deal from ASDA Mobile, giffgaff, Lebara Mobile, SMARTY or VOXI. All of them offer one-month rolling plans that you pay for in advance, with no credit check required.

At present, you can get 2GB of data from £5/month on a flexible SIM-only deal:

NetworkMinutesTextsDataMonthly
Cost
Lebara Mobile1,0001,0002GB£5.00
ASDA Mobile300Unlimited2.5GB£7.00
SmartyUnlimitedUnlimited2GB£7.00
giffgaffUnlimitedUnlimited2GB£8.00
VOXIUnlimitedUnlimited6GB£10.00

Because of the flexibility that’s available to you, it’s possible to change the plan you buy as frequently as every month (e.g. to get more data or to save money by changing to a plan with less data).

For more information, read our guide to SIM-only deals with no need for a credit check.

Best SIM Card For Download Speeds

For access to the fastest download speeds, pick a SIM card that gives you access to 5G coverage on a 5G-ready smartphone.

At present, you can get a 5G SIM-only deal for as little as £5/month, with plans available from multiple different networks.

The following table shows the cheapest 5G-ready SIM-only deals available on each network:

NetworkMinutesTextsDataMonthly
Cost
ThreeUnlimitedUnlimited1GB£5.00
12 months
O2UnlimitedUnlimited10GB£8.00
12 months
giffgaffUnlimitedUnlimited9GB£10.00
1 month
BT MobileUnlimitedUnlimited1GB£10.00
24 months
VOXIUnlimitedUnlimited15GB£15.00
1 month
Tesco Mobile5,0005,0006GB£15.00
12 months
VodafoneUnlimitedUnlimited5GB£15.00
24 months
EEUnlimitedUnlimited160GB£20.00
24 months

Our guide to 5G SIM-only deals has a full comparison of the options available on each network.

Best SIM Card For International Roaming

On most SIM-only deals, you’ll have access to international roaming. This allows you to continue using your smartphone when abroad in other countries. There are some notable exceptions to this, such as on Vodafone’s discounted Basics price plan which offers UK-only usage.

If you regularly travel abroad to other countries, we’d recommend getting a SIM card from Three. This is because their SIM-only price plans include the Go Roam offer which allows you to use your mobile phone in 71 destinations at no extra charge. This includes most European countries along with 20 destinations outside of Europe (including the USA, Australia, New Zealand and more).

NetworkMinutesTextsDataMonthly
Cost
ThreeUnlimitedUnlimited12GB£8.00
12 months
ThreeUnlimitedUnlimited30GB£12.00
12 months
ThreeUnlimitedUnlimitedUnlimited£16.00
12 months

You can also choose Vodafone’s Unlimited Max price plan which comes with roaming at no extra cost in 81 destinations through Global Roaming Plus. Alternatively, EE offers the Roam Further Pass as a swappable benefit on their Smart SIM cards allowing you to use your mobile phone in the USA, Canada, Mexico, Australia and New Zealand.

Best SIM Card For Unlimited Data

An unlimited data plan will allow you to use your mobile phone as much as you like without needing to worry about running out of data mid-month.

If you’re looking for a SIM-only deal with unlimited data, you can currently choose from ten different mobile networks.

The following table shows a selection of the cheapest unlimited data plans available on each network:

NetworkMinutesTextsDataMonthly
Cost
ThreeUnlimitedUnlimitedUnlimited£16.00
12 months
SmartyUnlimitedUnlimitedUnlimited£18.00
1 month
VodafoneUnlimitedUnlimitedUnlimited
2Mbps max
£22.00
24 months
giffgaffUnlimitedUnlimitedAlways-On£25.00
1 month
VodafoneUnlimitedUnlimitedUnlimited
10Mbps max
£26.00
24 months
Virgin MobileUnlimitedUnlimitedUnlimited£27.00
24 months
VodafoneUnlimitedUnlimitedUnlimited£30.00
24 months
O2UnlimitedUnlimitedUnlimited£33.00
18 months
VOXIUnlimitedUnlimitedUnlimited£35.00
1 month
Lebara MobileUnlimitedUnlimitedUnlimited£35.00
1 month
EEUnlimitedUnlimitedUnlimited£37.00
24 months

For more information, see our full round-up of unlimited data plans in the UK. As an alternative, you can also consider a zero-rated data plan which gives you unlimited data for use on certain services (e.g. for social media, video or music).

More Information

For further information about a specific SIM-only deal, please click through to the relevant website to learn more about it. Alternatively, you can read our in-depth reviews of mobile networks and tariffs in the UK.

Your Comments 144 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 144 comments from readers. You can add your own comment here.

  • Does a PAYG agreement charge a £1 every time you switch the phone on in the morning? if only to listen to FM radio? for 15 minutes? then switch off. or are PAYG phones
    only chargeable when downloading Apps, E mail, Google chrome ect?

    • Hi Charlie,
      Thanks for your comment. Are you referring to Vodafone Pay As You Go 1? If so, there’s more detailed information in the article about that plan, but you’ll only be charged when you make an outgoing call, when you send a text message or when you use mobile data on your phone (initially these are charged at 20p/minute, 20p/text and 20p/5MB, but this is capped at a maximum of £1/day). If you’re only using FM radio and browsing the internet over Wi-Fi, there should be no charge from any Pay As You Go provider for this.
      Ken

  • Technical Question:
    What happens when you put a 4G Cat-6 SIM in a 4G Cat-5 mobile router (in terms of performance)?
    — Let’s say you live in a major UK city like London, with an associated decent 4G network connection on all available networks.
    — Let’s say (according to one web page I viewed detailing median average tests) that EE is fastest, Vodaphone is second fastest, and 3 network is a bit slower (but less expensive).
    — Let’s say my priority is to save money on data costs rather than go for top performance, so I get a 3 network (or 3-owned Smarty) SIM, which is Cat-6, and put it into a Cat-5 mobile router, such as the TP-link M7350.
    Here’s the question:
    In such a case as described above, would I be restricting the potential data speeds of the Cat-6 network SIM by using it in a Cat-5 router?
    — Or in real world use, would it not make any difference for example, if the overall network speed is not able to reach the potential top speed (150 Mb/s) of the Cat-5 device anyway?
    I hope that makes sense.

    • Hi there,
      Thanks for your comment. To answer your question very generally: the weakest link will dictate the speeds you can get. For instance, if your network supports Category 6 and your device supports Category 4, you’ll only be able to get up to Category 4 speeds (dictated by the maximum your device can support). Similarly, if your network supports Category 6 and your device supports Category 12, you’ll only be able to get up to Category 6 speeds (dictated by the maximum your network can provide).
      In your specific case, I’m not sure there’s an appreciable difference between Cat5 and Cat6. As far as I can tell, both can theoretically give you up to 300Mbps. However, Cat6 does add support for a technology called carrier aggregation, which may sometimes give you faster speeds on some networks.
      Ken

  • Hi ken when able I plan to go to Dubai for about a month my current contract runs out at the end of the month so
    Which sim deal will allow me to roam included in the cost
    Should I do a data only sim for my tablet

    • Hi Alan,
      Thanks for your comment. Sadly, I’m not aware of any UK mobile network offering inclusive roaming when you travel to Dubai/the United Arab Emirates. One option would be Vodafone’s Roam-Further offer where you pay £6/day. Otherwise, you might be able to get a SIM card from one of the local networks upon arrival.
      Ken

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