You can often save hundreds of pounds per year by getting a low-cost SIM card for your mobile phone. We compare the UK’s best value smartphone SIM-only deals.

A great way to save money on your mobile phone bill is to change your tariff to a SIM-only deal. Compared to a normal mobile contract, you can usually save hundreds of pounds per year whilst keeping the same phone number as before. You’ll also get lots of flexibility with the choice of either a 1-month or 12-month contract.

In this article, we’ll review and compare the UK’s best value smartphone SIM-only deals. We’ll compare SIM-only deals from 14 different mobile networks: from the big names like EE and O2, to lower-cost virtual network operators like giffgaff, iD Mobile, Plusnet and Smarty.

SIM Only Deals: How Do They Work?

A SIM-only deal for your mobile phone gives you an monthly allowance of minutes, texts and mobile data. As SIM-only deals aren’t bundled with a handset, it’ll normally be cheaper and much more flexible switching to SIM-only.

Typically, most people will be able to save more than £100 per year switching from a normal mobile contract to a SIM-only deal. You’ll need to provide an unlocked smartphone to make the switch to SIM-only, and you’ll be able to keep your existing phone number with a PAC Code.

Here are three key things you should know when choosing a SIM-only deal:

1. You’ll always get coverage from EE, O2, Three or Vodafone.

  • EE
  • O2
  • Three
  • Vodafone

The UK has only four coverage providers: all other mobile networks will piggyback on one of the four.

When it comes to SIM-only deals, there are currently 14 mobile networks you’re able to choose from. While this appears to be fairly complicated at first glance, it’s worth being aware there are actually only four network coverage providers underlying all of the services.

Besides the four major networks (EE, O2, Three and Vodafone), you’ll find a number of “virtual network operators” piggybacking on coverage from one of the main providers:

When using a virtual network operator, you’ll have access to the same signal as if you were using the underlying provider directly. To find out more and to compare the coverage in your area, please see our list of UK mobile phone coverage checker tools.

2. You can keep your current mobile number.

It’s a straightforward process to keep your current phone number when moving to a SIM-only deal.

If you’re changing mobile networks, you’ll need to obtain a PAC Code from your old mobile network. The process of transferring your phone number takes about one working day: our PAC Code Finder can walk you through the process one step at a time.

3. You might need to unlock your smartphone.

If your smartphone was originally provided by another mobile network, it might be necessary for you to unlock it before you can use it on another network.

For more information about unlocking your handset, see our in-depth guides to unlocking an iPhone and unlocking a Samsung Galaxy smartphone.

Recommended Deals

The most suitable SIM-only deal depends on your requirements: there isn’t a universal “best SIM-only deal” for everyone. In this section, we’ll outline some of our recommended SIM-only deals with a number of key features.

For Flexibility & No Credit Check

If you want ultimate flexibility, without the need to undergo a credit check, our recommendation is to order a free SIM card from giffgaff.

On giffgaff, you can get unlimited minutes, unlimited texts and 3GB of 4G internet for £10/month. This is increased automatically to 4GB per month once you’ve been on the tariff for 3 months. On giffgaff, there’s no need to sign any contracts so you can join or leave at any time. giffgaff also works on a pre-paid basis so there’s no need to undergo a credit check for the service.

TariffMinutesTextsInternetMonthly
Cost
£7.50 Goodybag250Unlimited2GB£7.50
£10 GoodybagUnlimitedUnlimited3GB£10.00
£12 GoodybagUnlimitedUnlimited4GB£12.00
£15 GoodybagUnlimitedUnlimited8GB£15.00
£20 GoodybagUnlimitedUnlimited20GB£20.00
£25 GoodybagUnlimitedUnlimitedAlways-On£25.00

giffgaff is a low-cost sub-brand of O2 offering the same 2G, 3G and 4G coverage available to customers on O2. For more information, please see our in-depth review of giffgaff.

For Families & Spend Control

For families wanting a single combined bill for everybody’s usage, BT Mobile is our recommended network (specifically, their Family SIM offer).

With Family SIM, households can have up to five SIM cards on one combined bill. Each SIM card has its own individual allowance along with a built-in spend cap to prevent unexpected out-of-allowance charges. Customers will get an online dashboard for managing their family’s spending, and will have the ability to delegate control on a SIM card-by-SIM card basis. There are also discounts available when multiple family members join BT Mobile, with the size of the discount rapidly increasing as more family members join.

The following table shows the cost of your first BT Mobile SIM card, assuming you’re currently a BT Broadband customer. Additional Family SIM cards will come with a further discount on this price.

NetworkMinutesTextsInternetMonthly
Cost
BT MobileUnlimitedUnlimited4GB£10.00
inc. £5 discount
BT MobileUnlimitedUnlimited2GB£10.00
inc. £5 discount
BT MobileUnlimitedUnlimited3GB£12.00
inc. £5 discount
BT MobileUnlimitedUnlimited6GB£13.00
inc. £5 discount
BT MobileUnlimitedUnlimited10GB£15.00
inc. £5 discount
BT MobileUnlimitedUnlimited20GB£18.00
inc. £5 discount
BT MobileUnlimitedUnlimited10GB£18.00
inc. £5 discount
BT MobileUnlimitedUnlimited40GB£35.00
inc. £5 discount

For more information, please see our review of BT Mobile and the BT Family SIM offer.

For Tethering & Personal Hotspot

If you’d like to get your laptop or tablet connected on-the-go, it’s worth being aware that only certain mobile networks will allow you to tether and to share your data via a hotspot.

Some lower-cost mobile networks like iD Mobile and Virgin Mobile prohibit the use of tethering on their network. Sometimes, certain plans are also excluded from tethering on some networks e.g. Three doesn’t allow you to tether on lower-cost Essential price plans.

The following table shows some of our recommended SIM-only deals for customers who want to be able to tether:

NetworkMinutesTextsInternetMonthly
Cost
VodafoneUnlimitedUnlimited6GB£10.00
Tesco Mobile1,0005,0005GB£11.00
ThreeUnlimitedUnlimited4GB£11.00
giffgaffUnlimitedUnlimited4GB£12.00
O2UnlimitedUnlimited5GB£15.00
EEUnlimitedUnlimited20GB£20.00

For more information, see our in-depth guide to tethering on UK mobile networks.

For Fastest Download Speeds

If you want access to the fastest 4G download speeds, EE is our recommended network for a new SIM-only deal. With EE, you’ll have access to double-speed 4G, and speeds of up to 60Mbps.

TariffMinutesTextsInternetMonthly
Cost
EEUnlimitedUnlimited20GB£20.00
EEUnlimitedUnlimited20GB£21.00
EEUnlimitedUnlimited30GB£25.00
EEUnlimitedUnlimited40GB£35.00

For more information, see our guide to double-speed 4G and EE’s tariffs.

For International Roaming

For customers wanting inclusive international roaming in 71 destinations (including Europe, the USA, Australia, Brazil, Singapore and more), Three offers Feel At Home Around The World on their ‘Advanced’ Pay Monthly SIM cards.

With Feel At Home, you can use your normal UK allowances at no extra cost when travelling abroad.

NetworkMinutesTextsInternetMonthly
Cost
ThreeUnlimitedUnlimited4GB£11.00

On Three’s lower-cost Essential plans, Feel At Home is only available when you’re travelling in Europe. For more information, see our full review of the Feel At Home offer or Three’s official webpage.

For Unlimited Data

  • giffgaff
  • Three

For customers wanting the peace of mind of unlimited data, there are currently suitable SIM-only deals available from giffgaff and Three.

giffgaff has the cheapest available SIM card with unlimited data: just £20/month will get you Always-On data (unlimited downloads with 4G speeds on the first 9GB per month). Three has a higher entry-level price for all-you-can-eat data, but has no limits on 4G usage (subject to TrafficSense policies).

NetworkMinutesTextsInternetMonthly
Cost
giffgaffUnlimitedUnlimitedAlways-On£25.00
Virgin MobileUnlimitedUnlimitedUnlimited£25.00
ThreeUnlimitedUnlimitedUnlimited£27.00

For more information, please see our in-depth guide to unlimited data tariffs.

Deals By Price Range

For a full overview of SIM-only deals by price range, please jump to the relevant section of this article:

Less than £10/month

5 Pound Note
In the UK, you can get a SIM-only deal for less than £5/month.

If you’re looking for a super-cheap SIM-only deal, the cheapest options currently available on the market start from around £5/month.

Typically, the best value SIM cards in this price range come from iD Mobile and Plusnet Mobile (both of them offer 1-month rolling contracts). For instance, iD Mobile offers 250 minutes, 5000 texts and 2.25GB of internet for £5/month.

iD Mobile uses 3G & 4G coverage from Three while Plusnet Mobile offers 2G, 3G & 4G coverage from EE. iD Mobile is the own-brand mobile network from the Carphone Warehouse and Plusnet Mobile is the low-cost sub-brand of BT.

The following tables show a full list of SIM-only deals available for under £10/month:

12 month contracts

NetworkMinutesTextsInternetMonthly
Cost
VodafoneUnlimitedUnlimited500MB£6.00
Sky Mobile10p/min
Free for
TV customers
10p/txt
Free for
TV customers
500MB£6.00
Virgin Mobile1,500Unlimited1GB£7.00
Tesco Mobile5005,0001GB£7.50
VodafoneUnlimitedUnlimited3GB£8.00
Virgin Mobile1,500Unlimited2GB£9.00
Three200Unlimited500MB£9.00

1 month contracts

NetworkMinutesTextsInternetMonthly
Cost
iD Mobile150Unlimited500MB£3.99
iD Mobile500Unlimited1GB£5.00
giffgaff150500500MB£5.00
ASDA Mobile1252,000250MB£5.00
Plusnet Mobile250500500MB£6.00
ASDA Mobile300Unlimited1GB£7.00
SmartyUnlimitedUnlimited2GB£7.50
giffgaff250Unlimited2GB£7.50
Tesco Mobile2505,000250MB£7.50
iD Mobile500Unlimited4GB£8.00
Plusnet Mobile1,000Unlimited1GB£8.00

From £10/month

The vast majority of SIM only deals start from £10/month.

At the £10/month price point, there’s a huge variety of SIM-only deals.

On a 1-month contract, some of the best value deals are available from giffgaff, iD Mobile and Smarty. Our recommended deal is giffgaff’s £10 goodybag which gives you unlimited minutes, unlimited texts and 3GB of data (plus an extra 1GB of free data once you’ve been a customer for 3 months). giffgaff uses coverage from O2, whereas iD Mobile and Smarty use coverage from Three.

On a 12-month contract, the best value deals currently have a similar amount of data as on the 30-day contracts. However, you may be able to get additional benefits when choosing a 12-month plan. For instance, Three has an “Advanced” SIM-only deal with inclusive roaming in 71 destinations. Meanwhile, Vodafone offers a Basic SIM Only deal with unlimited calls, but usage is limited to inside the UK only.

12 month contracts

NetworkMinutesTextsInternetMonthly
Cost
VodafoneUnlimitedUnlimited6GB£10.00
Three600Unlimited1GB£10.00
Tesco Mobile1,0005,0005GB£11.00
ThreeUnlimitedUnlimited4GB£11.00
Vodafone500Unlimited500MB£11.00
EEUnlimitedUnlimited250MB£11.00
Virgin Mobile2,500Unlimited4GB£12.00
Sky Mobile10p/min
Free for
TV customers
10p/txt
Free for
TV customers
2GB£12.00
Virgin Mobile2,500Unlimited5GB£13.00
Vodafone1,000Unlimited2GB£13.00
O21,000Unlimited1GB£13.00
BT MobileUnlimitedUnlimited500MB£13.00
EEUnlimitedUnlimited1GB£14.00

1 month contracts

NetworkMinutesTextsInternetMonthly
Cost
iD Mobile500Unlimited7GB£10.00
Lebara MobileUnlimitedUnlimited4GB£10.00
SmartyUnlimitedUnlimited4GB£10.00
giffgaffUnlimitedUnlimited3GB£10.00
ASDA Mobile600Unlimited3GB£10.00
Plusnet Mobile1,500Unlimited2GB£10.00
Tesco Mobile5005,0001GB£10.00
giffgaffUnlimitedUnlimited4GB£12.00
ASDA Mobile800Unlimited4GB£12.00
iD Mobile1,000Unlimited6GB£12.50
Plusnet Mobile2,000Unlimited3GB£12.50
Vodafone500Unlimited500MB£13.00

From £15/month

15 Pound NotesThere are a wide variety of SIM-only deals to choose from at the £15/month price point. You can get a data allowance of up to 8GB per month, along with unlimited calling & unlimited texts on many mobile networks.

One of the best deals at this price range is Smarty’s £15 Large tariff. You’ll get 8GB of data along with unlimited calls and unlimited texts, plus a discount every month for your unused data.

The following SIM-only deals are currently available from £15/month:

12 month contracts

NetworkMinutesTextsInternetMonthly
Cost
Tesco Mobile5,0005,00015GB£15.00
O2UnlimitedUnlimited5GB£15.00
VodafoneUnlimitedUnlimited5GB£15.00
Sky Mobile10p/min
Free for
TV customers
10p/txt
Free for
TV customers
5GB£15.00
BT MobileUnlimitedUnlimited4GB£15.00
BT MobileUnlimitedUnlimited2GB£15.00
ThreeUnlimitedUnlimited8GB£16.00
ThreeUnlimitedUnlimited30GB£17.00
O2UnlimitedUnlimited10GB£17.00
VodafoneUnlimitedUnlimited10GB£17.00
EEUnlimitedUnlimited3GB£17.00
BT MobileUnlimitedUnlimited3GB£17.00
Virgin Mobile5,000Unlimited15GB£18.00
ThreeUnlimitedUnlimited12GB£18.00
BT MobileUnlimitedUnlimited6GB£18.00
O21,000Unlimited3GB£18.00

1 month contracts

NetworkMinutesTextsInternetMonthly
Cost
giffgaffUnlimitedUnlimited8GB£15.00
SmartyUnlimitedUnlimited8GB£15.00
iD MobileUnlimitedUnlimited8GB£15.00
Lebara MobileUnlimitedUnlimited6GB£15.00
ASDA Mobile1,000Unlimited6GB£15.00
Plusnet MobileUnlimitedUnlimited4GB£15.00
Tesco Mobile5,0005,0004GB£15.00
Vodafone1,000Unlimited1GB£15.00
Three600Unlimited1GB£15.00
ThreeUnlimitedUnlimited4GB£16.00
VodafoneUnlimitedUnlimited3GB£17.00
VodafoneUnlimitedUnlimited5GB£19.00

From £20/month

20 Pound NoteAt the £20/month price point, most mobile networks are offering unlimited calls and unlimited texts. You can also get huge amounts of data at this price point (e.g. 30GB of high-speed 4G data from Three).

For unlimited downloads and greater flexibility, we’d recommend choosing giffgaff’s £20 goodybag. For £20/month, you’ll get unlimited minutes, unlimited texts and Always-On data. There’s no need to undergo a credit check for the service, and there are also no contracts to sign.

The following deals are also available from £20/month:

12 month contracts

NetworkMinutesTextsInternetMonthly
Cost
ThreeUnlimitedUnlimited100GB£20.00
Tesco Mobile5,0005,00025GB£20.00
VodafoneUnlimitedUnlimited20GB£20.00
O2UnlimitedUnlimited15GB£20.00
EEUnlimitedUnlimited10GB£20.00
BT MobileUnlimitedUnlimited10GB£20.00
Sky Mobile10p/min
Free for
TV customers
10p/txt
Free for
TV customers
10GB£20.00
EEUnlimitedUnlimited20GB£21.00
O2UnlimitedUnlimited20GB£22.00
VodafoneUnlimitedUnlimited10GB£22.00
BT MobileUnlimitedUnlimited20GB£23.00
BT MobileUnlimitedUnlimited10GB£23.00
VodafoneUnlimitedUnlimited40GB£24.00
VodafoneUnlimitedUnlimited15GB£24.00

1 month contracts

NetworkMinutesTextsInternetMonthly
Cost
giffgaffUnlimitedUnlimited20GB£20.00
iD MobileUnlimitedUnlimited20GB£20.00
Lebara MobileUnlimitedUnlimited12GB£20.00
ASDA MobileUnlimitedUnlimited9GB£20.00
ThreeUnlimitedUnlimited30GB£22.00
VodafoneUnlimitedUnlimited10GB£22.00
ThreeUnlimitedUnlimited12GB£23.00

From £25/month

The following SIM-only deals are available for £25/month or more:

12 month contracts

NetworkMinutesTextsInternetMonthly
Cost
Virgin MobileUnlimitedUnlimitedUnlimited£25.00
O2UnlimitedUnlimited40GB£25.00
EEUnlimitedUnlimited30GB£25.00
ThreeUnlimitedUnlimitedUnlimited£27.00
VodafoneUnlimitedUnlimited25GB£27.00

1 month contracts

NetworkMinutesTextsInternetMonthly
Cost
giffgaffUnlimitedUnlimitedAlways-On£25.00
ASDA MobileUnlimitedUnlimited15GB£25.00
VodafoneUnlimitedUnlimited20GB£27.00

£30/month and more

The following SIM-only deals are available for £30/month or more:

12 month contracts

NetworkMinutesTextsInternetMonthly
Cost
VodafoneUnlimitedUnlimited45GB£31.00
Tesco Mobile5,0005,00050GB£35.00
EEUnlimitedUnlimited40GB£35.00
O2UnlimitedUnlimited40GB£35.00
BT MobileUnlimitedUnlimited40GB£40.00

1 month contracts

NetworkMinutesTextsInternetMonthly
Cost
ThreeUnlimitedUnlimitedUnlimited£32.00
VodafoneUnlimitedUnlimited30GB£32.00
VodafoneUnlimitedUnlimited40GB£37.00

More Information

For more information about the mobile networks listed in this article, please see our in-depth mobile network reviews. You may also find it helpful to read our guides on comparing mobile network coverage and how to transfer your phone number. If your smartphone was originally purchased from another network, you may also need to unlock it.

Prices change on an occasional basis. For this reason, you should always double-check the details on the mobile network’s website before signing up to any deal.

Your Comments 108 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 108 comments from readers. You can add your own comment here.

  • Martin Campbell said:

    Excellent and very informative site. Thank you. Question: If I buy a phone with a dual sim can I switch my number to both sim cards?

    • Hi Martin,
      Many thanks for your comment. With a PAC Code, you’ll be able to transfer your phone number onto one of the SIM cards. You can place that SIM card into your dual-SIM phone, but each of your two SIM cards will have a different phone number (as opposed to both SIM cards having the same number).
      Hope this helps,
      Ken

    • Hi Pat,
      Many thanks for your comment. Unfortunately, TalkTalk Mobile is currently closed to new customers so this is why we haven’t included them in this guide. It’s expected the service will re-launch later in the year using coverage from O2. However, there are also rumours TalkTalk will try to phase it out so they can focus on their core home broadband/TV/home phone service instead. Watch this space!
      Ken

  • Help! I can’t be the only dinosaur left in the UK. I use a phone to make phone-calls and the occasional text. .
    Talk mobile suited me down to the ground, but , sadly, Vodafone decided to shut it down.

    I did get a freeby (eventually!) to transfer to Voda. they are scandalously expensive for payg. Telepnone “help” is a joke, BUT they have opened a call-centre in Manchester…that works, they are English and understand the culture and don’t lose anything in the translation….5 minutes to sort -out a problem their foreign call – centre couldn’t resolve in 2 1/2 HOURS…..guess I won’t stay with them!

    What -about 1p? seems to fill my needs. PAYG, ancient (2g ) ? phone, cheap rate, long (4-months) active life for £10 credit- blocks. I’ll look again through your site but didn’t see that provider.

    next nearest for value appears to be ID, £3.50 a month is OK, but only 3G and newer phones. both deals appear to be better value than Asda……am I missing something?
    Great site, found you through Google.

    • Found your review on 1p. by far the cheapest option on payg, if I read the small print correctly…..anyway, I’ve signed up. Hate contracts, as prices seem to be dropping daily in this now-mature market, where all providers seem to be desperate to flog their airtime.

      It wouldn’t surprise me to see a return of the reduced evening and weekend tariff -structure, in order to sweat their assets a little bit more.

      • Hi Steve,
        Many thanks for the feedback! As you said, 1pMobile is a Pay As You Go option so they’re listed in a separate part of the website from these Pay Monthly SIMs 🙂 I think 1p is a good option if you’re a fairly light user with occasional usage. Of course, you just need to keep an eye out for the 120-day requirement (so I recommend you either use auto-topup or you put something in the diary to top up your account every 3 months).
        Ken

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