Mobile phone networks: a simple guide

Local mobile phone coverage not great? Fed up with your current supplier or desperate to see if you can switch to 5G? It’s always good to look at other mobile networks, big and small, to check coverage in your area and find deals to suit your budget.



Local mobile phone coverage not great? Fed up with your current supplier or desperate to see if you can switch to 5G? It’s always good to look at other mobile networks, big and small, to check coverage in your area and find deals to suit your budget.



Holly Cox
Digital expert
minute read
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Posted 25 MAY 2021

What’s a mobile network operator? (MNO)

Mobile network operators are companies that provide your mobile phone services. They provide the network that enables you to send and receive calls and texts, and access the internet. In the UK there are four main network operators.

Who are the biggest UK mobile networks?

The UK’s largest mobile networks include:
• EE
• O2
• Three
• Vodafone

These four phone networks supply the most customers and have the widest coverage in the country. They also support many of the smaller mobile virtual network operators, by providing them with access to their wider network. This is often referred to as piggybacking.

What is piggybacking?

‘Piggybacking’ is a term used to describe the way that mobile virtual network operators (MVNOs) provide coverage for their customers. Smaller mobile networks don’t typically have their own mobile networks, so they instead rent access to the networks supplied by the larger providers.

What’s a mobile virtual network operator? (MVNO) 

MVNOs are smaller operators that rent infrastructure, buy space from or piggyback one of the four main network providers.

This means that if you subscribe to one of these MVNOs, you’ll get the same coverage as you would with the main operator.

It’s usually worth knowing who the MVNO is piggybacking services from. If you have a bad signal or slow data speeds from one provider, there’s no point signing up with an MVNO who shares the same network.

Which mobile providers are powered by other mobile networks?

Giffgaff, Sky and Tesco are all large mobile plan providers, but none of them operate their own networks. These three are all examples of MVNOs who rent the services of even larger networks. Giffgaff, Sky and Tesco Mobile are all powered by O2.

See who some of the most popular networks are powered by:

Main provider MVNO renting space

Major players:  

  •  ASDA Mobile Mobile – but it has said it’s moving to piggyback Vodafone this year 
  •  BT Mobile
  •  The Phone Co-op
  •  Virgin Mobile Mobile – but changing to piggyback Vodafone in late 2021


  •  Plusnet Mobile
  •  Utility Warehouse
  •  Vectone Mobile 

Major players:  

  •  Giffgaff
  •  Tesco Mobile
  •  Sky Mobile  


  •  Lycamobile
  •  Glemnet (business mobile)

Major players:  

  •  iD Mobile 


  •  Smarty
  •  Superdrug Mobile

Major players:  

  •  Voxi
  •  TalkTalk mobile  


  •  Glemnet (businessmobile)
  •  Lebara Mobile

Which mobile phone network has the best coverage? 

It depends on how you define coverage. Some networks measure coverage by percentage of the population covered, while some organisations look at how much of the UK landmass gets a signal. Essentially, they don’t all measure coverage in the same way.

Mobile phone networks are now delivering a much more level playing field when it comes to 4G coverage across the UK. All of the major mobile networks have achieved almost complete coverage, aside from very rural areas. 

But there is hope for areas with poor or no signal. In March 2020 the Government agreed with the four largest mobile operators that they’d deliver a ‘Shared Rural Network’, with grant funding. Each mobile operator has agreed to deliver decent voice coverage and data to 90% of the UK’s landmass by 30 June 2026, subject to certain conditions. However, with Government priorities potentially stretched by the coronavirus pandemic, the targets could change.

Before you sign up to a network, use Ofcom’s mobile coverage checker to make sure you’ll receive a mobile signal in all the places where you’ll need it. Don’t forget to check both indoor and outdoor signal strength.

The 4G network is well established, and the 5G network of fifth generation wireless mobile phone technology is growing rapidly. But currently, 5G coverage across the UK isn’t widespread and it’s mostly concentrated around the bigger towns and cities.

Mobile network 4G Coverage (% of UK population)**
EE 99%
O2 99%
Three 99.8%


** The above percentages are based on information on the providers’ websites as of 10 December, 2020. 

EE were the first to launch 5G in the UK and made a strong start in getting towns and cities connected with the fastest speeds.

Mobile network 5G enabled towns and cities
EE 112
O2 108
Three 154


*** The above figures are based on information on the providers’ websites as of 10 December, 2020. 5G continues to be rolled out, so coverage is likely to increase.

Which is the best mobile phone network for customer service?

Customer service is pretty even across the board, which is great news for all mobile phone users. The big four providers appear to deliver a consistent level of customer service.

Which is the best phone network?

There are too many factors to crown an overall best mobile network. Your phone model, location, network coverage and data plan are just some of the things that make up a good phone network, with each provider performing better or worse in each area.

Ofcom runs reports on the main aspects of mobile providers’ services. In 2019, Ofcom’s Comparing Customer Service survey reported that EE and 02 both scored 93% for overall customer satisfaction. Vodafone scored 90% and Three achieved a score of 89%.

Which mobile networks provide 5G?

The launch of 5G began in the middle of 2019, with more mobile networks joining the race in 2020. Here are the mobile networks currently offering 5G in select locations:

  • BT
  • EE
  • O2
  • Sky
  • Tesco Mobile
  • Three
  • Vodafone
  • Voxi

Are there any disadvantages to using a smaller mobile phone network?

Not really. In terms of coverage and data speeds, you’ll get the same service as customers who buy their phone services direct from the big four networks.

Where you might be at a disadvantage when using a smaller provider is in being unable to qualify for any of the main network’s freebies and rewards – only those directly contracted to the big four will get these perks. 

How to choose a mobile provider

To compare deals, have an idea of what you’re looking for from a mobile provider price plan. Think about how many calls you make, texts you send or how much data you’d likely use. Find the price plan that best fits what you need.

Some things to consider when comparing mobile providers include:

  • Cost – data is often a big part of mobile cost, and, while it’s great to have unlimited data, if you’re only using 2GB a month, you don’t need to pay the extra for it.
  • Contract length – do you want to be tied into a long-term contract, or do you appreciate the freedom to switch when you need to? Common contract types range from rolling monthly plans, to two-year contracts. You normally find slightly better deals for longer contracts, but if flexibility is important to you, it could be worth paying the higher price.
  • Coverage – the big four mobile phone networks (EE, O2, Three and Vodafone) each have about 99% national 4G coverage. If you’re looking at a smaller provider, consider an MVNO which uses the network of a larger provider. If you want 5G, you’ll need to check if it’s available in your area and if so, who’s offering it. 5G is not available everywhere, but the 5G network is growing all the time.
  • Additional benefits and extras – some mobile providers will offer benefits like data rollover, free access to media streaming services or even priority access to events. 
  • service - if your mobile phone is vital to you, you may want to check the latest annual performance reports from Ofcom

Use our mobile comparison service today to compare phone providers and get a quick list of deals. 

Here’s a quick rundown of the main providers. Just remember, they’re offering special deals all the time (which are subject to change).

BT Mobile

Powered by EE’s mobile network, which is a part of the BT Group, BT Mobile accesses some of the best coverage in the country - over 99% of the UK. BT Mobile also supports 5G. It offers over 5 million WiFi hotspots across the country.

SIM-only contracts start from as little as just a few pounds a month. Selected deals may also include free access to the BT Sport app. BT Mobile offers a family deal where you can pay for up to five SIMs from one account, and get 20% off every extra SIM you add.


Part of the BT Group, EE was formed after combining previous mobile networks Orange and T-Mobile. It’s the largest mobile network in the UK and provides coverage for over 99% of the country. It was also the first network to support 5G in the UK.

EE offers contract phones, SIM-only deals, as well as pay as you go services.

EE has received several awards, including the UK’s best network, as judged by RootMetrics, for seven consecutive years. It was also again recognised as having the UK’s fastest and most reliable network by RootMetrics in 2020.
Rewards with EE have included months of free access to a range of media apps, like BT Sport, Amazon Prime Video and Apple Music.


Running on O2’s existing network, which covers approximately 99% of the UK, aside from the big four, giffgaff is now one of the country’s larger mobile operators.

Giffgaff started rolling out a 5G service in October 2020. The thing that’s different about giffgaff is that it’s run online by its members. There are no call centres. Instead, giffgaff has a team of what it calls ‘community helpers’ who can quickly answer customer questions online.

Also, giffgaff has received a number of network awards.
Giffgaff offers a variety of services, including buying phones outright or on a monthly contract, as well as SIM-only deals, with monthly rolling plans available. You can cancel whenever you want. SIM-only plans start from just a few pounds a month for 500MB of data. At the other end of the scale you can get an unlimited data SIM if you’re prepared to pay more.

If you want to save money on your phone, giffgaff also offers refurbished, pre-owned phones. All of these come with a 12-month warranty. If you want to upgrade, you can sell your old phone to them to get money off a new or refurbished device.

With giffgaff’s ‘Always On’ plans, it’s important to note that any usage that exceeds 80GB, will be throttled at a reduced speed of 384 kilobits per second (kbps) between 8am and midnight.

iD Mobile

Powered by Three’s network, iD Mobile receives approximately 99% coverage across the UK.

iD Mobile specialises in flexible, 30-day SIM-only plans. They also benefit from a data rollover perk, which allows you to keep any unused data for the next month, and so on. They also offer a variety of pay monthly phone contracts through their parent company, Carphone Warehouse.

All iD Mobile plans offer a bill-capping feature, which allows you to stop yourself from going over your own limit. This can be changed by you at any time.


With no long contracts to tie you down, Lebara offers flexible, 30-day rolling SIM-only plans that start from just a few pounds per month. You can also get their unlimited SIM-only plan if you pay more.

With a Lebara phone plan, you can add ‘Bolt Ons’, which allow you to quickly top up your account with extra data or phone minutes – including international minutes in 41 countries. This allows you to be flexible if you need the occasional boost.

Powered by Vodafone, you’ll stay connected almost anywhere in the country, with around 99% of the UK covered.


Second only to EE in terms of customer numbers, O2 is one of the UK’s ‘big four’ mobile phone networks, with coverage of 99% of the UK. 

O2 were also among the first UK networks to start rolling out 5G and now have 5G coverage in parts of 100+ towns and cities.

A variety of mobile plans are available, including pay as you go, SIM only and contract phone deals. 

O2’s ‘priority’ offers are some of the most wide-ranging phone network benefits. O2 customers receive free trials to services, discounts and invites to competitions, as well as priority access for tickets to concerts and events at O2 venues. 

O2 have also offered customers, on eligible new plans, six months free access to streaming service Disney+.



With its SIM-only deals starting from just £6 a month, Plusnet offers cheap and flexible plans that roll from one month to the next. There are a variety of packages available, with data limits to suit your usage. If you decide you need a top up, Plusnet offers data ‘bolt-ons’ that allow you to top up further. Plusnet broadband customers can also receive extra discounts or data boosts.

Plusnet is powered by EE’s vast network, which covers over 99% of the UK, and is owned by the BT Group.

Sky Mobile

Sky Mobile offers a selection of SIM-only and phone contract deals.

Key benefits to Sky Mobile customers include data rollover, allowing you to save any unused data for later, as well as the ability for Sky TV customers to stream unlimited through Sky Apps, without using any data.

‘Piggybacking’ off O2’s network, Sky Mobile offers coverage across almost the entire UK.

Smarty mobile

Smarty mobile offers SIM-only deals. These are rolling monthly deals, so you can switch or cancel when you need to.

One of Smarty’s bonuses allows you to get money back on unused data. Depending on your plan, you could get a few pounds back every month, simply for giving back the data you didn’t end up needing. 

Powered by Three, you can expect coverage for approximately 99% of the UK


Talkmobile offers both 12-month and rolling monthly SIM-only phone deals. Offers start from just £5 a month, while the rolling monthly contracts offer greater flexibility, allowing you to change and upgrade your deal if you need more data etc.

The mobile network has also offered limited time deals, when you can receive half-price plans for the first few months.

Talkmobile is powered by the Vodafone network, which means you’ll have reliable coverage that spreads across 99% of the UK.

Tesco Mobile

Tesco Mobile offers a combination of 12-month SIM-only contracts, as well as contract phone deals.

Powered by the O2 network, Tesco Mobile covers 99% of the UK, and also offers new 5G plans. 

Tesco Mobile also offers a variety of monthly perks, which can be swapped in or out each month. These range from extra data, more call minutes, extra Tesco Clubcard points, and even money off your phone bill. You can also opt for Family Perks - free monthly extras - if you’ve more than one number on your account. Each family member can choose their own perk, ranging from more data or minutes to extra Clubcard points, or money off your mobile insurance.

Tesco Mobile offer a variety of capped plans, as well as unlimited plans.

Three (3)

Three is among the UK’s ‘big four’ mobile networks and is also one of the most widespread 5G networks in the country. Three is currently offering 5G-ready plans at no extra cost. 

They specialise in ‘all you can eat’ data plans, which means you can browse online as much as you’d like with your own personal hotspot, handy when there’s no WiFi for your other devices.

Three’s Go Roam now offers customers the opportunity to use their call, text and data allowances in 71 destinations around the world at no extra cost (up to fair usage limits – see Three’s fair use policy for more information).

Three offer a mix of pay as you go, SIM only and contract phone deals. Three is known for offering bundles, adding free tech gifts to eligible deals.

Virgin Mobile

Virgin Mobile offers a wide range of services, including contract phones, SIM-only deals and even SIM-free phones. You can also get a range of tablet devices with data packages.

Benefits to Virgin Mobile customers include flexible plans, allowing you to tailor your package each month. They offer data rollover plans too, so you can hang on to anything you don’t use up. Also, data used on a number of messaging apps like WhatsApp and Messenger won’t eat into your normal data plan. 

Using EE’s mobile network, Virgin Mobile customers benefit from 4G coverage across more than 99% of the UK. Free WiFi is available at 3.5 million hotspots too.


One of the UK’s ‘big four’ networks, Vodafone offer coverage across 99% of the UK. They also have enabled 5G in a number of locations across the UK.
Vodafone offers a combination of pay as you go, SIM only and contract phone deals.

Their ‘VeryMe’ rewards scheme provides a wide range of weekly treats and giveaways. This can include small things like a free coffee or snack, all the way up to exclusive access to event tickets.

Vodafone have won several awards, including nPerf’s Best Mobile Internet Performance 2019 award.


Voxi is a mobile network that promises “endless social media data”. Their plans offer sizeable data allowances, including unlimited data, but you won’t eat into any of that while using selected social media apps. These include Facebook, Messenger, WhatsApp, Instagram, Twitter and Snapchat.

Voxi is powered by the Vodafone network, which offers coverage across 99% of the UK. Voxi also offer a series of 5G plans, for even fast connectivity.

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