Mobile networks like giffgaff, Lycamobile, Sky Mobile and Tesco Mobile piggyback on O2’s 2G, 3G and 4G coverage.

The UK has four network coverage providers: EE, O2, Three and Vodafone. Each of the coverage providers maintain a network of mobile phone masts, licensing spectrum from the government and operating the physical towers. Alongside them, there’s a group of virtual network operators like giffgaff and Sky Mobile that “piggyback” on coverage from one of the four coverage providers.

At present, there are 6 other mobile networks that ‘piggyback’ on coverage from O2. If you’re a customer of one of these mobile networks, you’ll have access to the exact same coverage as customers on O2. This includes O2’s 99% population coverage on 2G, 3G and 4G (but not Wi-Fi Calling and 4G Calling as these are O2-specific services).

In this article, we’ll review the mobile networks piggybacking on O2 coverage, which will often give you larger allowances for a lower monthly price. We’ll compare the best value SIM cards at a range of price points, from £5/month up to more than £20/month.

Mobile Networks Using O2 Coverage

The following table shows a list of mobile networks using coverage from O2. On all of these mobile networks, you’ll have coverage wherever an O2 signal is normally available:

Mobile NetworkCoverage Provider2G3G4G5GCoverage Checker
C4C MobileO2Check C4C Mobile Coverage
CUniqO2Check CUniq Coverage
giffgaffO2Check giffgaff Coverage
LycamobileO2Check Lycamobile Coverage
O2O2Check O2 Coverage
Sky MobileO2Check Sky Mobile Coverage
Tesco MobileO2Check Tesco Mobile Coverage

As of January 2018, O2 mobile contracts are also being promoted by TalkTalk to their broadband & home phone customers. This replaces the old TalkTalk Mobile service (previously using coverage from Vodafone), with TalkTalk customers receiving a fully-branded O2 service.

For a complete list of other mobile networks and the coverage providers they’re using, see our in-depth guide to mobile phone coverage in the UK.

Tariff Information & Coverage Information

For more information about each mobile network, click on the relevant logo to visit the mobile network’s website:

If you’re a customer of O2 directly, you’ll have access to O2 customer-exclusive features such as O2 Priority. These offers are not available to customers of a virtual network operator, but there may be other network-specific features or offers (e.g. Sky Mobile’s data piggybank feature or giffgaff’s Payback rewards).

Deals By Price Range

In the rest of this article, we’ll compare the best value SIM cards using coverage from O2. All of the deals are separated out by price range and tariff type (e.g. Pay Monthly and Pay As You Go).

Please select your preferred price range to see a list of currently available deals:

Pay As You Go

If you’re looking for a traditional Pay As You Go tariff where you’re able to pay on a per-minute, per-text and per-megabyte basis, you’re currently best off on O2’s Classic Pay As You Go tariff. On Classic Pay As You Go, you’ll pay 3p/minute, 2p/text and 1p/MB. This even undercuts the price offered by virtual networks like giffgaff, who charge 15p/minute, 5p/text and 5p/MB.

Alternative Pay As You Go networks for more specialist usage include Lycamobile (which offers low-cost international phone calls), C4C Mobile (which offers inclusive charitable donations) and CUniq (which offers you a Chinese or Hong Kong phone number on your UK SIM).

Less than £10/month

If you’d like a SIM card for less than £10/month with coverage from O2, you can currently choose from giffgaff, Lycamobile, Sky Mobile and Tesco Mobile.

On a Pay Monthly contract, Sky Mobile offers SIM cards on a 12-month contract. If you’re a Sky TV customer, you’ll get unlimited calls and unlimited texts are included in the plan. For everyone else, it’s either an extra £10/month, or you can Pay As You Use at 10p/minute and 10p/text.

For the ultimate in flexibility, it’s worth having a look at Pay As You Go bundles, especially from giffgaff. Of particular note, giffgaff offers the £8 goodybag with 500 minutes, unlimited texts and 2GB of data.

Pay Monthly Contracts

Sky MobileUnlimitedUnlimited2GB£6.00
Tesco Mobile5005,0001GB£7.50
Tesco Mobile2505,000250MB£7.50

Pay As You Go Bundles

Tesco Mobile100100250MB£5.00
Tesco Mobile250500500MB£7.50

From £10/month

There are numerous deals available from £10/month with coverage from O2.

Our current recommendation is giffgaff’s £10 goodybag which gives you unlimited minutes, unlimited texts and 3GB of data. It’s a Pay As You Go bundle so there’s no need to sign a contract or undergo a credit check. Also, once you’ve been a customer of giffgaff for 3 months, you’ll get an extra 1GB of data, boosting your monthly allowance up to 4GB per month.

The following table shows Pay Monthly contracts and Pay As You Go bundles from £10/month with coverage from O2:

Pay Monthly Contracts

Tesco Mobile5005,0004GB£10.00
Tesco Mobile5005,0001GB£10.00
Sky MobileUnlimitedUnlimited4GB£12.00
Tesco Mobile5,0005,00010GB£14.00

Pay As You Go Bundles

Tesco Mobile5005,0003GB£10.00
Tesco Mobile5005,0004GB£12.50

From £15/month

The following deals are available from £15/month, and include coverage from O2:

Pay Monthly Contracts

Sky MobileUnlimitedUnlimited8GB£15.00
Tesco Mobile5,0005,0004GB£15.00
Tesco Mobile5,0005,00020GB£18.00

Pay As You Go Bundles

Tesco Mobile1,0005,0006GB£15.00

£20/month and more

The following deals are available from £20/month with coverage from O2. For £25/month, giffgaff offers the £25 goodybag with unlimited minutes, unlimited texts and Always-On data (unlimited downloads with 4G speeds on the first 20GB per month). This is available as a Pay As You Go bundle, so there’s no need to sign a contract or to undergo a credit check.

Pay Monthly Contracts

Tesco Mobile5,0005,00050GB£25.00
Sky MobileUnlimitedUnlimited25GB£25.00
Tesco Mobile5,0005,00030GB£30.00

Pay As You Go Bundles

Tesco Mobile2,0005,0008GB£20.00

For more information about data speeds and tethering, tap the data allowances in the table above. For Pay Monthly contracts, you can tap the mobile network’s logo for information about the length of the contract.

More Information

For more information, see our in-depth guide on how mobile phone coverage works in the UK. You can also see our in-depth reviews of each UK network.

Your Comments 7 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 7 comments from readers. You can add your own comment here.

  • Joseph hague said:

    I have been a giffgaff customer for a few years now,and have been very happy with it,until my internet connection went and there is no one to contact about it?

    • M bethell replied:

      You can look on giffgaffs website and email a adviser with you problem. To be fair I have been with giffgaffs for years and if I have ever had I problem it has been sorted out in a timely manner

  • I want a low usage tariff like O2’s ‘Classic Pay As You Go’, but I am confused by their terms and conditions.

    In one section it states you must Top Up every 6 months
    Classic Pay As You Go
    When you join Classic Pay As You Go, you pay for what you use, as you go. The minimum
    top up requirement is £10.
    ‘If you don’t top up, or add a Bolt On at least once in any six month period, your mobile will be
    disconnected and you’ll lose any credit on your account. If you want to be reconnected you’ll
    be given a new mobile number.’

    But in the Terms and Conditions paragraph 7.1. it states that you are only required to use the SIM every 6 months
    7.1. If you do not carry out any chargeable activity at least once in any 6 month period your
    Mobile Phone will be disconnected and you will lose any remaining credits balance on your
    Account. If you wish to be re-connected after this time you will be given a new Mobile Phone

    Do I have to only use the SIM every 6 months as it states. Or do I need to ‘Top Up’ £10 every 6 months as well as using the SIM?

    • Hi Grant,
      Thanks for your comment. This is a question that lots of people have discussed in the comments on my full guide to O2 Classic Pay As You Go. I believe the general consensus is this was sloppy wording from O2, and you just had to use your phone for a chargeable activity once every 6 months. However, if this is likely to be an issue, I’d recommend double-checking directly with O2.

  • Christopher Pugh said:

    Hi Ken, Your article is very interesting. I have been on Tesco Mobile PAYG Lite for some time, at 8p per minute for calls and 4p for texts. I use a simple phone on this service for calls only. (I have a smartphone on the “3” network for data use). Can I really change to O2’s Classic PAYG tariff at 3p per call and 2p per text, with the only conditions that need to be satisfied are a minimum top up of £10 and one call must be made every six months. It sounds identical to Tesco Lite at 3/8 of the call cost, or have I missed something?

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