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

The UK has only four network coverage providers: EE, O2, Three and Vodafone. Alongside them, a group of virtual network operators such as giffgaff and Sky Mobile operate by ‘piggybacking’ on the signal from one of the four big networks.

At present, five other mobile networks piggyback on coverage from O2. If you’re a customer of one of these mobile networks, you’ll have access to the same coverage as customers on O2. This includes O2’s 99% population coverage on their 2G, 3G and 4G networks (excluding O2-specific services like Wi-Fi Calling and 4G Calling).

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

Mobile Networks Using O2 Coverage

The following table shows a list of mobile networks using coverage from O2. On all of these networks, you’ll be able to get coverage wherever a normal O2 mobile signal is available:

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

As of 2019, the biggest players in this list are giffgaff, Sky Mobile and Tesco Mobile. Some of the smaller networks focus on specific international segments (e.g. Lycamobile offers low-cost international calling where CUniq offers you a Chinese or Hong Kong phone number on your UK SIM card).

For a complete list of 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 individual network, tap 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 could be other network-specific features or offers (e.g. Sky Mobile’s data piggybank or giffgaff’s Payback rewards).

Deals By Price Range

Through the rest of this article, we’ll compare the best value SIM cards using coverage from O2. We’ve separated the deals out by price range and tariff tariff (into Pay Monthly SIM cards and Pay As You Go SIM card with no need for a credit check).

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

Under £10/month

For less than £10/month, you can get a SIM card from giffgaff, Lycamobile, Sky Mobile or Tesco Mobile giving you coverage from the O2 network.

On a Pay Monthly contract, it’s worth having a look at the deals from Sky Mobile. They’re often quite aggressively priced, and include unlimited streaming through Sky apps if you’re a Sky TV customer.

For greater flexibility with no need for a credit check, order a free SIM card from giffgaff. They offer a £6 goodybag on a Pay As You Go basis with 300 minutes, 500 texts and 500MB of data. Alternatively, you can get the £8 goodybag with 500 minutes, unlimited texts and 2GB of data.

Pay Monthly Contracts

Sky MobileUnlimitedUnlimited3GB£6.00
Tesco Mobile5005,0002GB£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 6GB of data. It’s a Pay As You Go bundle so there’s no need to sign a contract or to undergo a credit check. Also, once you’ve been a giffgaff customer for 3 months, you’ll get an extra 1GB of data, boosting your allowance to 7GB per month.

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

Pay Monthly Contracts

Tesco Mobile05,0005GB£10.00
Sky MobileUnlimitedUnlimited9GB£12.00
Tesco Mobile5,0005,00010GB£12.50

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

Tesco Mobile5,0005,00025GB£15.00
Tesco Mobile5,0005,00020GB£15.00
Sky MobileUnlimitedUnlimited10GB£15.00
Tesco Mobile5,0005,00030GB£18.00
Sky MobileUnlimitedUnlimited15GB£18.00

Pay As You Go Bundles

Tesco Mobile1,0005,0006GB£15.00

£20/month and more

For £20/month, giffgaff offers 40GB of data along with unlimited minutes and unlimited texts. This is available on a one-month rolling deal (Pay As You Go), so there’s no need to sign a contract or to undergo a credit check.

For an extra £5/month, you can upgrade this to Always-On data with the £25 goodybag (unlimited downloads with the first 40GB per month at full 4G speeds).

The following table shows a list of deals available from £20/month with coverage from O2:

Pay Monthly Contracts

Tesco Mobile5,0005,00060GB£20.00
Tesco Mobile5,0005,00060GB£22.00
Tesco Mobile5,0005,00050GB£25.00
Sky MobileUnlimitedUnlimited25GB£25.00
Tesco Mobile5,0005,000100GB£30.00

Pay As You Go Bundles

Tesco Mobile2,0005,0008GB£20.00

For more information about download speeds and tethering, tap the data allowances in the table above. You can tap on the mobile network’s logo for information about the length of the contract.

Traditional 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 with O2’s Classic Pay As You Go plan. On Classic Pay As You Go, you’ll pay 3p/minute, 2p/text and 1p/MB. This undercuts the price offered by virtual networks like giffgaff, who charge 15p/minute, 5p/text and 5p/MB.

Other Pay As You Go networks could be better for more specialist usage. For instance, Lycamobile offers low-cost international phone calls using O2 coverage on Pay As You Go.

More Information

For more information, see our full guide to mobile phone coverage in the UK and our in-depth guide to O2’s mobile network and coverage. You can also read our in-depth reviews of each UK mobile network.

Your Comments 8 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 8 comments from readers. You can add your own comment here.

  • I live in a remote area and want to use 4g as my main broadband. O2 are the only ones who have a strong enough signal. They have an unlimited data deal, but the small print says you can only use it in a phone and not a ‘modem’. Seems crazy, as I could tether a phone and use just as much data, but it would be messy compared to a dedicated 4g router/modem… I’ll probably need about 400Gb per month.

  • 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?

  • Damian Morgan said:

    Great article, very helpful. Having read this I’ve been able to make an easy comparison between all the O2 based providers and move to a SIM Only deal saving myself over £10 B month! Many thanks

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