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8 October 2021

How to buy the best mobile phone

Apple or Android? Cheap or premium? Find out how to choose right phone, get the best deal, and which brands are most reliable.
Which? Team
Mobile deals advice2 476298

A great mobile phone will take the place of your camera, keep you informed and entertained on the move and still leave you with enough battery when you get home.

But it's not easy to find a model that can succeed on all counts. With prices rising and more than ever to choose from, it's important to spend your money wisely on a phone that will last. 

Read our in-depth guide for advice on choosing the right operating system, brand and additional features that you'll really use.

Or head straight to the best mobile phones we've found in our tough tests.

Which? is bringing legal action against Qualcomm. If you bought an Apple or Samsung phone after 1 October 2015, you could be affected.

Video: how to buy the best mobile phone

How much do I need to spend for a good mobile phone?

You could spend over £1,000 on a smartphone, but fortunately over recent years we've seen excellent models for a fraction of the price.

Expect to spend a little over £200 for a Best Buy. It may not have all the bells and whistles of premium competitors, but any phone good enough to be a Best Buy is guaranteed to tick a lot of boxes.

What you're typically missing out on versus the flagship models are high end cameras and high resolution video, a less sharp or colourful display, and less premium materials in the phone's construction.

What you can get, regardless of price, are perfectly capable and versatile cameras that take great photos, impressive battery life, and processors that are more than fast enough for most day to day tasks.

Looking for a bargain? Read our full list of the best mobile phone deals, or compare mobile phones and Sim-only contracts and find out how much you could save.

The importance of security in a phone purchase

One important consideration for any phone purchase is how long it'll received important security updates from the manufacturer.  This is where brand can make a difference. Apple traditionally supports smartphones for the longest, at around 5 or 6 years. Android brands vary considerable, from 2 to over 4 years. 

This isn't always easy to work out, and you need to remember that support durations start from when the phone is released, not when you buy it. To help inform a purchase, enter a phone into the tool below to see our estimate of the minimum remaining support.

For more information on keeping a smartphone safe from hackers, read our guide to mobile phone security. 

iOS or Android: which OS is best?

The operating system (OS) is the software that powers your phone. It shapes what the phone interface looks like and what apps it can run, and plays a large part in how easy it is to use. There are two main players to choose from: iOS (Apple iPhones) and Android.


Android is designed by Google and is used by a range of manufacturers, from bigger brands such as Samsung and Motorola to growing brands like OnePlus and Oppo. Android looks and behaves slightly differently depending on who manufactures the smartphone handset, but the basics are essentially the same.

  • Pros It’s generally easy to use, extremely customisable and provides access to the wide variety of apps, games and entertainment available from the Google Play store. There are also plenty of Android phones to choose from whatever your budget.
  • Cons In the past, Android has been slightly more vulnerable to attack than Apple handsets. That's beginning to change now, though - Google is putting more emphasis on vetting apps in the app store and patching security holes before they're released. Sometimes manufacturers and network providers can be slow to release Android updates to users.

Apple iOS

All iPhones use iOS and, unlike Android, the experience of using the operating system is broadly similar whichever iPhone you buy. New updates to iOS are released each year, but some older iPhones may be able to run only older versions, which means you'll miss out on some of the latest features and security patches.

  • Pros Easy to use and quick to learn, even if you haven’t used a smartphone before. It provides access to the well-stocked Apple app store – where apps are vetted before being released, so you can rest assured they’re safe to use.
  • Cons Apple iPhones are expensive. If you're not obsessed with having the latest tech, you can find cheaper deals on older handsets, though. Apple iPhones also do not come with a micro-SD card slot, so you’ll need to choose the memory capacity carefully to avoid running out of space for your app, music and photo collection.

What size of phone should I buy?

Smartphones are getting bigger, with the latest high-end models measuring between 5.5 and 6 inches or more. While bigger phones are great for watching films and browsing the web, they won’t suit everyone. Some people find them too large and awkward to hold, and would prefer a model they can comfortably use with one hand.

The best way to find out which handset size is right for you is to try holding a few in a shop. Also pay attention to the physical dimensions of the phone. Screen sizes are available at different aspect ratios, and different phones have different sized bezels. A phone with a 6-inch screen may ultimately be smaller than one with a 5.5-inch screen.

Which mobile phones have the best battery life?

You might be tempted to think that phones with larger batteries have a better battery life. While battery size is a good indicator, that's not always the case. There are multiple things that can drain a phone's battery, including screen size, resolution and refresh rate, and the type of processor.

We put all phones through a rigorous battery test to find out how long they last under real usage conditions – watching videos, browsing the internet, making calls, using the camera and more, and we factor in idle time as well, to give a realistic usage time, and attribute a star rating.

If battery is the most important thing to you, you can browse all our reviews of phones with the best battery life to find a model that lasts.

Should I buy a phone on contract or Sim-free?

This is a key buying decision. It can be tempting to opt for a lower monthly fee rather than pay a lot outright for a new phone, but this could cost more in the long term. Use our phone contract calculator to find the best way to buy.

Should I buy a second hand phone?

One way to get a good discount on a phone is to buy second-hand, or a refurbished model – which is usually a phone that has been used but restored to 'as new' condition, or graded to a certain level of quality. The second hand phone market is a popular one, but you do need to be careful what you buy. Read more in our guide to buying a second-hand or refurbished mobile phone.

Which mobile phone brand is most reliable?

The biggest fault people have with mobile phones is related to battery, with almost one in five reporting issues with phones refusing to charge, or quickly losing charge.

We collect reliability data on all the big brand smartphones so you have all the very best advice before you buy. Read our guide to the most reliable smartphone brands for more.

Other mobile phone brands: Motorola, Google, Xiaomi and more

There's plenty of choice in the smartphones market outside Samsung and Apple, and plenty of quality too - we regularly uncover Best Buys from rival brands.


A popular 'budget' brand, Motorola has a range of very competitively priced models, and are a favourite among users who don't want to spend a fortune on a phone. Our tests have shown that it's capable of both Best Buys and Don't Buys, so check our Motorola mobile phone reviews to make sure your money's spent wisely.


If you're after a brand that provides value for money, look no further than Xiaomi. While it does produce high end phones, Xiaomi has a wide range of cheap yet feature-packed models that have seriously impressed. It is capable of producing a stinker though, so read our Xiaomi smartphone reviews before you buy.


Google aims for quality over quantity - it has a limited range but the phones are popular with budding smartphone photographers, and those who appreciate timely operating system updates - Google does own Android, after all. Browse our Google smartphone reviews to see if they tick the  boxes elsewhere.


OnePlus has really upped its game in recent years, and its flagships can now challenge those of Apple and Samsung. Prices have risen as well, though, so you might want to consider a range of cheaper OnePlus models. Head to our OnePlus smartphone reviews to check them out.

Other mobile phone brands

We've tested nearly 200 mobile phones to bring you a definitive verdict on your next model – from old-hands Sony and Nokia to new kids on the block Oppo and Realme. Browse all our mobile phone reviews to find the perfect model.

Where to buy a mobile phone

When buying a mobile phone, make sure you're handing your money over to a reputable seller. Check the retailer's returns policy and pay attention to customer feedback and reviews. For more details on shopping online safely and arranging refunds for faulty products, see our advice on shopping online

Mobile Phones Direct, Argos and Carphone Warehouse are some of the most searched-for mobile phone retailers at the time of writing. We’ve included links to these retailers handpicked because of their stock availability, best value price or warranty options. 

  • Mobile Phones Direct – from Sim-free and Sim-only to pay monthly or refurbished, mobile phones direct (part of the AO family) stocks hundreds of phones that are delivered using free next day delivery direct from UK manufacturers. It offers deals with 18 different brands including Apple, Samsung, Huawei and Google with one of three network options; Vodaphone, O2 and Three. 
  • Argos – sells a mixture of Sim-free and Pay as you Go mobile phones. Prices start at less than £20 for basic models and go up to around £1,300. Argos offers same day in-store collection at selected Sainsbury's stores and you can even bump up your nectar points when you shop there. 
  • Carphone Warehouse – specialist mobile phone retailer that stocks lots of different phones from a range of network providers. You can opt for Sim-only or a monthly contract and you can even trade in your old phone when you upgrade. Carphone Warehouse promises to price match if you find a cheaper deal elsewhere and they offer free home or in-store delivery. 
  • Mobiles.co.uk –part of Carphone Warehouse, it's always worth checking this site as well, especially if you're looking to buy on contract. They often have good deals on handsets, though make sure you've added up all extras – including upfront costs. Look for the total price paid, rather than getting seduced by price per month.