SIM-only deals can save you money on your mobile phone bill every month. Discover and compare the 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 you’ll normally get lots of flexibility with either a 12-month or a 1-month rolling contract.

In this article, we’ll review SIM Only deals in the UK 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 be given a new SIM card that slots into your smartphone and will be billed for your usage of the SIM card each month.

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 possible to take your current phone number with you. This is a fairly straightforward process and only involves you requesting a PAC Code from your old mobile 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 simply slot inside your current smartphone. There’s no need to backup or transfer any data: your phone book, photos, messages and other data will still be there on your phone after you do this.

If your mobile phone was previously used on a different 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 EE, O2, Three or Vodafone Coverage

Regardless of which mobile network you choose, you’ll always be getting coverage from one of the big four (that’s EE, O2, Three and Vodafone).

Other mobile networks simply piggyback on coverage from the big four:

  • Networks using EE coverage include ASDA Mobile, BT Mobile, Plusnet Mobile and Virgin Mobile.
  • Networks using O2 coverage include giffgaff, Sky Mobile and Tesco Mobile.
  • Networks using Three coverage include iD Mobile and SMARTY.
  • Networks using Vodafone coverage include Lebara Mobile and VOXI.

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 mobile phone contract. For instance, you might need to pay more than £50/month for the latest iPhone on a 24-month contract with 4GB of data. The equivalent SIM-only deal would cost you around £10/month, giving a saving of about £500 per year.

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

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 119 of 119 price plans that match your criteria

NetworkMinutesTextsInternetMonthly
Cost
iD Mobile500Unlimited1GB£5.00
1 month
Lebara Mobile500Unlimited1GB£5.00
1 month
giffgaff300500500MB£5.00
1 month
ASDA Mobile200Unlimited500MB£5.00
1 month
Sky MobileUnlimitedUnlimited2GB£6.00
12 months
iD MobileUnlimitedUnlimited1GB£6.00
1 month
VodafoneUnlimitedUnlimited500MB£6.00
12 months
SmartyUnlimitedUnlimited1GB£6.25
1 month
ASDA Mobile300Unlimited2GB£7.00
1 month
Three200Unlimited2GB£7.00
12 months
Plusnet MobileUnlimitedUnlimited1GB£7.00
12 months
Virgin Mobile1,500Unlimited1GB£7.00
12 months
SmartyUnlimitedUnlimited2GB£7.50
1 month
Plusnet MobileUnlimitedUnlimited1.5GB£7.50
1 month
Tesco Mobile5005,0001GB£7.50
12 months
VodafoneUnlimitedUnlimited3GB£8.00
12 months
giffgaff500Unlimited2GB£8.00
1 month
Plusnet MobileUnlimitedUnlimited2GB£8.50
1 month
Virgin Mobile1,500Unlimited6GB£9.00
12 months
iD MobileUnlimitedUnlimited3GB£9.00
1 month
Plusnet MobileUnlimitedUnlimited3GB£9.00
12 months
ThreeUnlimitedUnlimited8GB£10.00
12 months
VOXIUnlimitedUnlimited6GB£10.00
1 month
VodafoneUnlimitedUnlimited6GB£10.00
12 months
SmartyUnlimitedUnlimited4GB£10.00
1 month
Lebara MobileUnlimitedUnlimited4GB£10.00
1 month
Superdrug MobileUnlimitedUnlimited4GB£10.00
1 month
ThreeUnlimitedUnlimited4GB£10.00
24 months
Plusnet MobileUnlimitedUnlimited4GB£10.00
1 month
ASDA Mobile600Unlimited4GB£10.00
1 month
Tesco Mobile5005,0004GB£10.00
12 months
giffgaffUnlimitedUnlimited3GB£10.00
1 month
O21,000Unlimited2GB£10.00
18 months
Tesco Mobile5005,0001GB£10.00
1 month
Plusnet MobileUnlimitedUnlimited5GB£11.00
12 months
VodafoneUnlimitedUnlimited1GB£11.00
12 months
O21,000Unlimited1GB£11.00
12 months
iD MobileUnlimitedUnlimited6GB£12.00
1 month
ASDA Mobile800Unlimited5GB£12.00
1 month
giffgaffUnlimitedUnlimited4GB£12.00
1 month
Sky MobileUnlimitedUnlimited4GB£12.00
12 months
ThreeUnlimitedUnlimited4GB£12.00
12 months
ThreeUnlimitedUnlimited12GB£13.00
24 months
Plusnet MobileUnlimitedUnlimited6GB£13.00
1 month
VodafoneUnlimitedUnlimited1GB£13.00
1 month
iD MobileUnlimitedUnlimited10GB£14.00
1 month
Tesco Mobile5,0005,00010GB£14.00
12 months
O2UnlimitedUnlimited4GB£14.00
12 months
BT MobileUnlimitedUnlimited1GB£14.00
12 months
Virgin Mobile5,000Unlimited25GB£15.00
12 months
VOXIUnlimitedUnlimited15GB£15.00
1 month
ThreeUnlimitedUnlimited12GB£15.00
12 months
Plusnet MobileUnlimitedUnlimited12GB£15.00
1 month
Plusnet MobileUnlimitedUnlimited12GB£15.00
12 months
giffgaffUnlimitedUnlimited8GB£15.00
1 month
Sky MobileUnlimitedUnlimited8GB£15.00
12 months
SmartyUnlimitedUnlimited8GB£15.00
1 month
ASDA Mobile1,000Unlimited8GB£15.00
1 month
Lebara MobileUnlimitedUnlimited6GB£15.00
1 month
VodafoneUnlimitedUnlimited5GB£15.00
12 months
Tesco Mobile5,0005,0004GB£15.00
1 month
BT MobileUnlimitedUnlimited3GB£15.00
12 months
iD MobileUnlimitedUnlimited14GB£16.00
1 month
O2UnlimitedUnlimited10GB£16.00
18 months
ThreeUnlimitedUnlimited4GB£16.00
1 month
EEUnlimitedUnlimited1GB£16.00
12 months
O2UnlimitedUnlimited9GB£17.00
12 months
BT MobileUnlimitedUnlimited8GB£17.00
12 months
BT MobileUnlimitedUnlimited5GB£17.00
12 months
VodafoneUnlimitedUnlimited5GB£17.00
1 month
O2UnlimitedUnlimited3GB£17.00
12 months
ThreeUnlimitedUnlimited30GB£18.00
24 months
Tesco Mobile5,0005,00020GB£18.00
12 months
ThreeUnlimitedUnlimited12GB£19.00
1 month
EEUnlimitedUnlimited3GB£19.00
12 months
ThreeUnlimitedUnlimited100GB£20.00
12 months
VOXIUnlimitedUnlimited45GB£20.00
1 month
giffgaffUnlimitedUnlimited40GB£20.00
1 month
ThreeUnlimitedUnlimited30GB£20.00
12 months
O2UnlimitedUnlimited25GB£20.00
12 months
iD MobileUnlimitedUnlimited20GB£20.00
1 month
VodafoneUnlimitedUnlimited20GB£20.00
12 months
ASDA MobileUnlimitedUnlimited12GB£20.00
1 month
Lebara MobileUnlimitedUnlimited12GB£20.00
1 month
BT MobileUnlimitedUnlimited12GB£20.00
12 months
ThreeUnlimitedUnlimitedUnlimited£22.00
12 months
ThreeUnlimitedUnlimitedUnlimited£22.00
24 months
O2UnlimitedUnlimited40GB£22.00
18 months
EEUnlimitedUnlimited25GB£22.00
12 months
VodafoneUnlimitedUnlimited20GB£22.00
1 month
VodafoneUnlimitedUnlimitedUnlimited£23.00
12 months
O2UnlimitedUnlimited15GB£23.00
12 months
BT MobileUnlimitedUnlimited15GB£23.00
12 months
ThreeUnlimitedUnlimited30GB£24.00
1 month
giffgaffUnlimitedUnlimitedAlways-On£25.00
1 month
SmartyUnlimitedUnlimitedUnlimited£25.00
1 month
VodafoneUnlimitedUnlimitedUnlimited£25.00
1 month
EEUnlimitedUnlimited50GB£25.00
12 months
Virgin Mobile5,000Unlimited50GB£25.00
12 months
Tesco Mobile5,0005,00050GB£25.00
12 months
Sky MobileUnlimitedUnlimited25GB£25.00
12 months
Lebara MobileUnlimitedUnlimited20GB£25.00
1 month
ASDA MobileUnlimitedUnlimited15GB£25.00
1 month
ThreeUnlimitedUnlimitedUnlimited£26.00
1 month
VodafoneUnlimitedUnlimitedUnlimited£26.00
12 months
O2UnlimitedUnlimited60GB£26.00
18 months
Virgin MobileUnlimitedUnlimitedUnlimited£27.00
12 months
VodafoneUnlimitedUnlimitedUnlimited£28.00
1 month
O2UnlimitedUnlimited50GB£28.00
12 months
VodafoneUnlimitedUnlimitedUnlimited£30.00
12 months
O2UnlimitedUnlimited60GB£30.00
12 months
Tesco Mobile5,0005,00030GB£30.00
12 months
BT MobileUnlimitedUnlimited20GB£30.00
12 months
VodafoneUnlimitedUnlimitedUnlimited£32.00
1 month
BT MobileUnlimitedUnlimited40GB£32.00
12 months
EEUnlimitedUnlimited20GB£32.00
12 months
EEUnlimitedUnlimited40GB£37.00
12 months
O2UnlimitedUnlimited40GB£38.00
12 months
EEUnlimitedUnlimited60GB£47.00
12 months

You can scroll through the full list of price plans to see currently available deals that match your criteria. If you’re unsure about how much data you want on your plan, see our guide to mobile download limits. As of 2019, the average smartphone user consumes about 2GB of data per month in the UK.

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 more expensive plan with lots of data that you don’t 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:

Data AllowanceCheapest PlanCheapest Mobile Network
500MB Data£5.00/monthiD Mobile & Lebara Mobile
1GB Data£5.00/monthiD Mobile & Lebara Mobile
2GB Data£6.00/monthSky Mobile
3GB Data£8.00/monthVodafone
4GB Data£9.00/monthVirgin Mobile
8GB Data£10.00/monthThree
12GB Data£13.00/monthThree
20GB Data£15.00/monthVirgin Mobile
100GB Data£20.00/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 network coverage from EE, O2, Three and Vodafone.

Once you’ve figured out the coverage providers that work in your area, it’s then worth being aware of which mobile networks piggyback on each provider. Piggyback mobile networks offer the same level of coverage as the mobile network they use.

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 £7/month on a flexible SIM-only deal:

NetworkMinutesTextsInternetMonthly
Cost
ASDA Mobile300Unlimited2GB£7.00
SmartyUnlimitedUnlimited2GB£7.50
giffgaff500Unlimited2GB£8.00
VOXIUnlimitedUnlimited6GB£10.00
Lebara MobileUnlimitedUnlimited4GB£10.00

Because of the flexibility that’s available on the plans, you can 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).

The lowest prices are currently available on ASDA Mobile which uses coverage from EE, but there are also options that use coverage from O2 (giffgaff), Three (SMARTY) and Vodafone (Lebara Mobile and VOXI).

Best SIM Card For Download Speeds

In the UK, the fastest download speeds are currently available on EE’s 5G Smart SIMs. As long as you have a 5G-ready smartphone and as long as you live in a 5G coverage area, you’ll be able to get super-fast 5G download speeds. You’ll also get two Swappable Benefits included with your SIM card:

NetworkMinutesTextsInternetMonthly
Cost
EEUnlimitedUnlimited20GB£32.00
12 months
EEUnlimitedUnlimited40GB£37.00
12 months
EEUnlimitedUnlimited60GB£47.00
12 months

Other mobile networks are due to launch a 5G service later in 2019. Vodafone will launch their 5G service on the 3rd July 2019 with Three launching their 5G service in August 2019. O2 is still yet to announce their 5G launch date, but it is expected before the end of 2019.

If you have a 4G smartphone, the fastest download speeds also tend to be available on EE.

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 a further 20 destinations that are outside of Europe (including the USA, Australia and New Zealand).

NetworkMinutesTextsInternetMonthly
Cost
ThreeUnlimitedUnlimited8GB£10.00
ThreeUnlimitedUnlimited4GB£10.00
ThreeUnlimitedUnlimited12GB£13.00
ThreeUnlimitedUnlimited30GB£18.00
ThreeUnlimitedUnlimited100GB£20.00
ThreeUnlimitedUnlimitedUnlimited£22.00

Aside from Three’s SIM only deals, EE’s 5G Smart SIMs have an optional “Roam Further” swappable benefit. This gives you inclusive roaming in the USA, Canada, Mexico, Australia and New Zealand. Vodafone’s Unlimited Max plan includes roaming in a further 29 destinations outside Europe. Most other mobile networks only offer inclusive roaming when you’re travelling within Europe.

Best SIM Card For Unlimited Data

If you’re looking for a SIM-only deal with unlimited data, you can choose from giffgaff, Three, SMARTY, Vodafone or Virgin Mobile.

All of these plans will allow you to use your mobile phone as much as you like without you needing to worry about running out of data mid-month.

NetworkMinutesTextsInternetMonthly
Cost
ThreeUnlimitedUnlimitedUnlimited£22.00
12 months
VodafoneUnlimitedUnlimitedUnlimited£23.00
12 months
giffgaffUnlimitedUnlimitedAlways-On£25.00
1 month
SmartyUnlimitedUnlimitedUnlimited£25.00
1 month
Virgin MobileUnlimitedUnlimitedUnlimited£27.00
12 months

On Vodafone, the maximum download speeds you can access will differ depending on which unlimited plan you choose. You can get up to 2Mbit/s speeds on the Unlimited Lite price plan (£23/month), up to 10Mbit/s on the Unlimited plan (£26/month) and uncapped speeds on the Unlimited Max plan (£30/month).

With giffgaff’s Always-On Data, you’ll get 4G speeds on the first 40GB per month. After this, maximum download speeds will be restricted to 384kbit/s between 8am and midnight each day. Unlimited data plans from other mobile networks have no such restrictions on download speed.

Virgin Mobile’s unlimited data plan is only available to Virgin TV and home broadband customers.

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 more information on specific SIM-only deals, please click through to the relevant mobile network’s website. You can also read our in-depth mobile network and tariff reviews.

Your Comments 123 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 123 comments from readers. You can add your own comment here.

  • Hi Ken,
    Lebara Mobile are now offering 1GB, 500 minutes UK, 100 minutes to 41 countries and unlimited texts for £5 on a monthly rolling contract. So far I can’t see any obvious snags so this looks like good value.

    • Hi Richard,
      Thanks for the heads up on the update to the Lebara Mobile SIM! I’ve updated the above so it’s reflected with the new allowances.
      Thanks again!
      Ken

  • andrew lee said:

    Hi Ken. When I search the Vodafone website I don’t see SIM-only prices anywhere near as low as quoted by you (e.g. 3GB is £15 compared to your £8). Am I missing something? Thanks v much, Andrew.

    • Hi Andrew,
      Thanks for your comment. Yes, click through the link provided to see the 3GB for £8 tariff. There are some little-known Vodafone Basics price plans (see full review here) which you won’t find through the main navigation on their website.
      Ken

      • andrew lee replied:

        Great, thanks, v useful. I notice that MMS isn’t available on the Vodafone basics. Do you know if this would prevent me sending a photo via email when I’m out and about using 4G, i.e. using my own Mail account app? I’m guessing it wouldn’t as Mail is OTT but maybe I’m wrong. Thanks v much. Andrew. PS – my wife thinks your site is great ….. it was her that pointed me to it 🙂

        • Hi Andrew,
          Haha – great! I’m really pleased to hear that you both like the site!
          Regarding MMS, yes, this only stops you from sending a MMS message. It doesn’t stop you from sending photos a different way (e.g. using e-mail, WhatsApp, Twitter, iMessage, or something else). To be honest, people rarely use MMS these days so it isn’t a massive disadvantage in my opinion (but it’s something they can remove from the plan to dissuade some people from choosing the cheaper tariff “just in case” they need it).
          Ken

  • Hi Ken,

    We’re going to England for a month and want to use data and phone and text while we’re there. What’s our best option

    • Hi Perry,
      Thanks for your comment. Are you visiting from outside the UK? If so, you’ll be looking for a prepaid SIM card & ideally one that allows you to use a non-UK card. I’ve written more about this in my guide for visitors to the UK, but in short, giffgaff will normally be the best option. They offer 3GB data, unlimited minutes & unlimited texts for £10/month.
      Hope this helps,
      Ken

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