Choosing a smartphone or tablet is just the start. In this world of constant connectivity the quality and speed of your chosen network is critical to your ability to work and play on the move. But which mobile network is best? While there's no simple answer, we try our best to help you decide which network will work for you.

Connectivity can vary from locale to locale, and day to day. Visit the websites of all the major players and they will tell you that they have great coverage, everywhere. The truth is more nuanced.

Interestingly, according to StatCounter, October 2016 was the first time that more people accessed the internet on a mobile phone or tablet than they did on a desktop or laptop PC. It recorded 51.2 percent mobile against 48.7 percent desktop, making it all the more important that you choose the best mobile network.

If you've already got a contract and are considering buying a new phone or switching to a different network, here's how to find out how long is left on your contract, and then how to upgrade your contract early.

It's important to make sure you know when your contract ends in order to ensure that you are not being over charged. According to Citizens Advice, more than six million people are still being charged for mobile phones they've already paid for.

What's the best phone network in the UK?

Here we take a quick look at each operator and what they offer right now. We've listed them in alphabetical order. 

BT Mobile

BT is fairly new to the market, and uses its branded services on EE’s UK network. It’s a good option if you already have BT Broadband as you can apply for a £5 monthly discount on a contract with a handset. 

It also offers SIM-only plans for pretty decent prices. As it’s on EE’s network (which itself is a combination of the old UK networks T-Mobile and Orange) you’re likely to get excellent coverage and good download speeds.

EE

EE is becoming a bit of a behemoth in the UK mobile market. It was bought by BT in 2016, but that won’t really affect your choice of network. EE’s network is comprised of the old T-Mobile and Orange frequencies, so there’s a lot of coverage nationally, with few blackspots. 

Its phone contract prices can be a tad pricey, but for sheer confidence in coverage (and a big brand name to boot) it’s a solid choice.

Plus, Apple Music (which is already offered for free for six months if you sign up to an EE contract) doesn't eat into your data allowance on EE.

Giffgaff

Owned by O2, Giffgaff is a little operator but one with attractive SIM-only deals. Using its owners network, it offers 2GB of data on plans from as little as £10 a month. It’s a fine choice if you already own a handset – just get a SIM and you’re good to go. However it does offer phones on a contract if you need both. 

Giffgaff won consumer watchdog uSwitch’s Network of the Year 2016, so it’s clearly doing something right. 

O2

O2 is a brand that has been around since 2002 in the UK and has been owned by Telefonica since 2005. Recently rival operator Three attempted to merge with O2 but the European Commission opted to block the move (this was in the wake of the BT and EE sale).

Despite this, O2 is one of the most well-known operators around. Its prices are high compared to some competitors but coverage is excellent and its pay as you go range is one of the best in the country. 

Sky Mobile

The newest addition to the UK mobile market, Sky has become a ‘quad-play’ provider by adding mobile to its TV, broadband and landline offerings. 

Existing Sky customers get the best deals, with free calls and texts. You just pay for how much data you want, on a plan that uses O2’s network. Non-Sky customers can pay £10 extra per month for unlimited calls and texts. If you want to use Sky for everything, now you can.

Tesco Mobile

Another user of O2’s big UK network, Tesco Mobile provides contracts, pay as you go and SIM-only deals at decent prices. Again, because it uses O2’s network coverage will be decent and often the subsidies for new handsets are good. 

SIM-only prices can be under £10 per month, so if you’ve got a handset you already love it could save you a lot of money. 

Three

Three is unique in that it offers reasonably priced ‘all you can eat’ data bundles. That’s right, unlimited data. If you can afford it, you can get the best handsets in the land with unlimited Internet access.

Plus, even if you don't choose an all-you-can-eat package, you'll be able to stream shows from Netflix, TVPlayer, Dave and History Channel, and songs drom Deezer and SoundCloud infinitely without it counting towards your data allowance.

Pay as you go rates are also pretty decent if you don’t need as much data, minutes or texts. Three unsuccessfully attempted to buy O2, and the fact it didn’t is good for the mobile market. More competition means better prices for you the consumer.

Virgin Mobile

Virgin was late to the party with 4G, but has caught up and is an attractive option if you already get your broadband connection and TV from Virgin, cutting down the number of tech providers you gave to deal with.

Vodafone

Vodafone is a staple brand in the UK mobile market, and its coverage is excellent. We will say that in our own personal experience and also in the media recently it has suffered thanks to bad customer service. However, the actual network itself provides incredibly reliable fast 4G data connections and the SIM-only deals are well priced.

You may want to shop around if you feel that the contract prices are too high; they often are around the launch of a handset but if you can wait a few weeks they generally come down. We continuously share the best phone deals here.

According to a study by RootMetrics, EE is the provider of the best mobile coverage across the UK. If you're in England or Wales, Vodafone is the second-best option, while Northern Ireland and Scotland's runner up is O2.

uSwitch Awards

In February 2017, uSwitch unveiled the winners of its Mobile Awards 2016, voted for by more than 5,000 consumers and a judging panel of journalists.

Giffgaff was declared the best mobile network, with Tesco Mobile in second place and Three in third. Vodafone was the only one of the big UK mobile networks not to scoop a first-place award in any category.

Best Mobile Network of the Year

1. giffgaff
2. Tesco Mobile
3. Three

Best Pay Monthly Network

1. Three
2. Tesco Mobile
3. O2

Best PAYG Network

1. Tesco Mobile
2. O2
3. Vodafone

Best SIM-only Network

1. giffgaff
2. Tesco Mobile
3. Three

Best for Roaming

1. Three
2. O2
3. giffgaff

Best Customer Experience

1. Virgin Media
2. O2
3. Amazon

Best for Data

1. giffgaff
2. Three
3. O2

Best Network Coverage

1. O2
2. Three
3. EE

Network Customer Service

1. giffgaff
2. O2
3. Three

Best Value Pay Monthly

1. Tesco Mobile
2. Three
3. Virgin Media

Best Value SIM Only

1. giffgaff
2. Tesco Mobile
3. Virgin Media

Fastest Mobile Network powered by RootMetrics

1. EE
2. Vodafone
3. O2

Ofcom research

in April 2017, Ofcom published its research into the service quality of the UK's telecoms providers. The research was carried out during the calendar year 2016.

Ofcom found that O2 and Vodafone customers were the most satisfied with their reception, with 86% of customers claiming to be satisfied. 85% off EE's customers said they were satisfied with their reception, while 80% of Three's said the same.

If you'd like to test the availability of mobile networks in your area, you can do so using Ofcom's mobile and broadband checker tool here.

Podcast discussion: Sky enters the mobile market