Mobile phones: compare and choose with confidence

Why you can trust Which? customer scores

To find out which mobile networks you can rely on, we ask the people who know best: their customers. Every year, we survey thousands of mobile network customers to learn more about the service they receive, and we use the information to create our mobile network reviews.

We ask mobile customers everything – from how much they spend each month to the type of contract they have. We also get them to rate the key elements of their mobile service, such as the reliability of their connection, the customer service and technical support from their provider and value for money. We also find out about the frustrations they face – incorrect bills, poor coverage and excessive communication, or long waits to speak to customer service advisers.

We then create ratings that enable us to compare each provider's performance, and we give each mobile network a Which? customer score based on customers’ overall satisfaction with the provider and their likelihood to recommend it.

Which? Recommended Providers

We name the best mobile networks Which? Recommended Providers (WRPs). These companies are the top performers, and only mobile networks with a customer score of 75% or above are eligible.

But that's not all. We also expect them to have strong star ratings and for their contracts to be below the market average price in the pricing analysis we conduct.

Which? Great Value providers

Great Value mobile networks offer Sim-only contracts that include a useful amount of data for most people, at a price far cheaper than the market average.

Eligible providers must also have a strong customer score – although we’ll consider those that aren't quite good enough to be WRPs.

We conduct a rigorous pricing analysis looking at the variety of deals on offer. We don't only look at the headline price – we also factor in both introductory offers and price rises to check whether deals that might look attractive actually end up costing over the odds.

Adam Snook, Which? mobile networks expert, says:

‘Choosing a new mobile network may seem like a daunting task, but our comparison service can help. Our customer scores and provider overviews are invaluable for weighing up the pros and cons of mobile networks before you sign up.

‘Increased competition between networks, particularly new, smaller providers, means exceptional deals are available.

‘Many phone users can switch to a cheaper deal with more data than they currently have. You can also look for a network with better connectivity in your area.

‘Switching has also never been easier – the introduction of Text to Switch means all you need to do is text your provider, rather than go through the hassle of calling them.

‘Even if you ultimately decide not to switch, details on the deals available to you are still invaluable when it comes to haggling with your current provider. Making note of competitive offers from its rivals is a key part of the arsenal you can use to negotiate.’

Can I switch mobile networks?

If your contract with your provider has ended, you’re free to switch mobile networks without paying an early termination charge.

If you’re not sure, you can find out by texting INFO for free to 85075, and you’ll get a text back detailing if you’re out of contract or if any early termination fees would apply to leaving your network.

Some networks may send a follow-up text requesting your date of birth to confirm your identity.

This service is provided by telecoms regulator Ofcom and can help customers easily understand their situation. It doesn't start a switching process or have any other impact on your mobile plan, so you're free to decide what to do next once you have this information.

If you are out of contract, it’s likely you’ll be able to find a better deal elsewhere.

How to switch mobile networks?

Text to Switch has made switching mobile network easier than ever. You need a porting authorisation code (PAC), which you get with a simple text message from your current network provider.

Previously, to get a PAC you had to call your provider, which would often try to deter you from switching and make the process frustrating.

To switch and keep the same mobile number, text PAC to 65075. Your current mobile provider should send you a text within one minute, and the PAC lasts for 30 days. The text will also have important information such as any charges for early termination (although this won’t apply if you’re out of contract). Give the PAC to your new provider, which has to complete the switch within one working day.

To switch and change your number, text STAC to 75075 to receive your service termination authorisation code, then follow the same procedure as if you’d received a PAC.

For more information on switching, such as how to switch if you're in a contract, and how to choose a provider with the best signal, read our full guide on how to switch mobile provider.

Can I keep my number if I switch networks?

Yes. To switch and keep the same mobile number, text PAC to 65075. Your current mobile provider should send you a text within one minute, and the PAC lasts for 30 days.

How does switching mobile networks work?

The cancellation and switching process begins automatically when you give your PAC or STAC to your new network.

The new network will contact your old network to set up the switch. Usually, this should happen the next working day.

Make sure you keep your existing Sim card in your phone so you can still make calls, send texts and use data while the switch takes place.

Once it stops working, insert your new Sim card or activate your eSim, then try calling someone or using data.

How long does it take to switch phone networks?

Switching should take one working day, so consider this when you start the switching process by giving a new network a PAC or STAC.

Ideally, pick a weekday such as Monday, Tuesday or Wednesday to avoid delay.

If you wait until Friday, Saturday or Sunday, it could take longer and your transfer may not be complete until the next Tuesday.

How much mobile phone data do I need?

Many people can get away with a small amount of data (less than 5GB) if they are often using a wi-fi network (eg at home or in an office) or don’t use their phone for more intensive online activities like video streaming.

As a rough guide, here’s how much data typical phone tasks use:

• 1.5 MB – send 100 emails (without attachments)
• 5 MB – 15 minutes looking at Facebook
• 25-60MB – an hour browsing the web
• 70 MB – stream one hour of high-quality music through Spotify
• 600 MB – download a regular (non-HD) 45-minute TV show from iTunes
• 1.1 GB – stream an HD TV show for one hour on BBC iPlayer
• 1.3 GB - stream a football match on Sky Sports Mobile TV
• 3GB – stream one hour of Netflix.

Many contracts now offer unlimited minutes and texts. As a result, it tends to be data that drives the price of a phone contract and the more you want, the more you pay.

For people who like to consume media on the move – and outside a wi-fi connection – huge data contracts might make sense. But unless your package is truly unlimited, you should still keep track of how much you're using. Be wary of contracts that have data in the triple digits or are unlimited, as you could be overpaying significantly compared to what you're actually using.

Which providers offer free mobile roaming?

Some mobile networks allow you to use data for free while travelling. Others charge you for daily or weekly passes.

These mobile networks allow you to use your included data for EU roaming but have a limit before you’ll be charged extra:

• Giffgaff - 5GB
• iD Mobile - 30GB
• Lebara - 30GB
• O2 - 25GB
• Smarty - 12GB
• Talkmobile - 5GB
• Tesco - same amount as your contract, or 25GB roaming limit if your contract includes more than 25GB

How do I find out when my phone contract ends?

You can text INFO for free to 85075 and you’ll get a text back detailing if you’re out of contract or if any early-termination fees would apply to leaving your network.

How to cancel a phone contract

If you’re on a rolling 30-day Sim-only contract you can switch to a new network without any extra costs.

On longer contracts, generally if you want to exit early you will have to pay penalty fees. These can be as high as 97% of the remaining monthly payments.

You can leave your contract early without paying exit fees if:

• You’re within the 14-day cooling-off period of signing the contract
• Your monthly price has been increased above the initially agreed terms
• You’re within 30 days of the contract ending

Usually, if you’re stuck in a contract you’re unhappy with, it’s best to wait it out then switch at its conclusion to a cheaper deal.

Should I buy a phone on contract or outright, with a separate Sim?

If you're shopping for a new phone, make sure you look at the total cost before getting a long-term contract.

If you can buy the phone outright, paired with a low-cost Sim-only deal for just the right amount of data you need can help make future payments more predictable. And with plenty of 30-day rolling contracts to choose from, it's easy to switch provider if you see something better.

This also breaks the contract cycle of continually getting a new contract with the same network. The bigger networks will encourage sales of the latest flagship phones and large data contracts, which you may not need. There are plenty of excellent phones available at a lower price.

Our mobile phone contract calculator can help you work out whether contract or Sim-only is the way to go.

How can I get a phone contract with bad credit?

The best option if you are concerned about your credit history is to go for a rolling 30-day Sim-only contract.

Many providers don’t perform credit checks for these contracts, and you’ll be able to find some great deals from networks such as Smarty, Giffgaff, Voxi and Lebara.

If you don’t already own a phone, pairing a Sim-only deal with a cheap phone bought outright is the best approach.

Do mobile phone providers offer social tariffs?

Yes. Eligibility varies but usually you need to receive one or more of the following:

• Universal Credit
• Pension Credit
• Income Support
• Employment and Support Allowance (ESA)
• Jobseeker’s Allowance (JSA)

As Sim-only contracts are generally quite affordable, with many exceptional deals around, some social tariffs are actually not the best value available. However, some are worthwhile, such as:

• Voxi - unlimited data for £10 a month
• Smarty - unlimited data for £12 a month

Do I need a 5G Sim?

All the UK’s mobile networks now have 5G capacity, and only a few budget or legacy contracts are 4G-only, so almost any Sim you get should be 5G ready.

However, 5G coverage around the country varies dramatically, so although your Sim is capable of a 5G connection, it may not often receive one.

You can use our mobile quality checker map to see how different networks perform in your area, to help you decide which to use.