What are Piggyback telephone networks? UK MVNOs Explained

There are many mobile operators in the UK, but many rely on the networks provided by the big four: EE, O2, Three and Vodafone.

So, who uses which network and what are the benefits of using a piggyback service? Here’s everything you need to know about them.

What is an overlay telephone network?

Setting up a mobile phone network is no easy task. You need transmitters and other expensive infrastructure that costs huge amounts of money, so it’s not feasible for many companies to create them.

To offset some of these costs, network owners allow others to pay to use them. This is why they are called piggyback services.

However, they are officially known as MVNOs, which stands for Mobile Virtual Network Operators.

What are the main networks in the UK?

There are four main networks:

In 2023, Three and Vodafone announced plans to merge, but the approval and finalization process will take some time, if at all. So at present we still have four major suppliers in the UK.

Additionally, thanks to MVNOs, there is a much wider choice for obtaining a SIM card, and often at a much lower cost than using one of the main four.

Here’s a list of the main MVNOs in the UK and which ‘real’ networks they use. This is important because coverage varies from country to country, and if you want 5G, it’s wise to check if it’s available where you live, work, and go regularly.

Here are the top MVNOs in the UK.

Which MVNOs use the EE network?

Which MVNOs use the O2 network?

Which MVNOs use the Three network?

Which MVNOs use the Vodafone network?

Advantages of a piggyback mobile operator

While it might seem obvious to get a SIM card directly from EE, O2, Three or Vodafone – the people who actually own the networks – there are good reasons to choose a piggyback operator.

As these MVNOs do not have additional costs related to maintaining and improving networks, this allows them to offer serious benefits to their customers.

That’s why one of the features of piggyback service providers is that you can usually get cheaper plans by signing up with them. This is especially true if you keep your existing phone and opt for a SIM-only deal.

As an example, at the time of writing, O2 has a SIM-only deal including unlimited calls, unlimited texts and 12GB data for £17.99 per month, and it’s a two-year contract.

Alternatively, Giffgaff (which uses the O2 network) offers the same deal but with 40GB of data instead, for £15 a month and you can cancel at any time as it’s a rolling monthly contract. Clearly a much better value for money.

Artur Tomala / Foundry

As the pricing mentioned above shows, MVNOs are free to offer more flexibility in their plans, making it more likely that you’ll be able to find one that suits your needs. One of the biggest benefits is that many offer rolling monthly plans where you can stop paying at any time and switch to another provider if you find a better deal.

You may still want to sign up for a longer contract, but at the other end of the scale there are pay-as-you-go plans which mean you only pay for the data, calls and texts you make. That’s the kind of freedom you typically won’t get with one of the big four networks.

If you’re traveling or want to try another network, monthly rollover options pose little risk because you won’t be tied into a long-term contract. This can be especially useful if you’ve just moved to a new location and found that your existing network coverage isn’t very strong there.

Disadvantages of an overlay mobile operator

One thing you don’t understand are the bonus features that are often used by big networks to entice them to choose them. These may include free subscriptions to streaming services, store discounts, or other entertainment perks.

For example, the Three+ incentive program includes deals at Cineworld, Caffe Nero, Nike, Uber Eats and more, as well as access to pre-sale tickets to concerts and festivals. O2 priority is very similar.

Artur Tomala / Foundry

Another thing is that you may also find that the range of phones available on big network plans is better than on MVNOs. So if you’re thinking of buying a new phone with your plan, it’s worth checking out a few different networks before signing up.

Ultimately, support is also worth considering. To offer a cheaper service, you may find that a piggyback operator does not have telephone support. If you need help, you may need to fill out an online form. For example, Giffgaff relies heavily on the support of its own community.

There are two different services which are MVNOs but also sub-brands of the larger networks. These are Smarty, part of Three, and Voxi, part of Vodafone. Both have great deals, so you can get the best of both worlds if you want to use the Three or Vodafone networks.

Why choose a piggyback mobile operator?

For most people, getting a SIM card from Lebara, Tesco or one of the other piggyback providers will save a lot of money and give more freedom to change whenever you want.

You might miss out on the various incentives offered by the big networks, but the money you save is definitely worth more. Notably, you’ll get the same coverage and speeds (many MVNOs now offer 5G as standard) as well as roaming options.

As with any phone plan, you should check the latest offers from network operators and those who operate them. And as you might expect, we’ve rounded up the best SIM deals just to save you time.

For more details, take a look at our roundup of the best phone networks and the best Pay As You Go networks in the UK.