Which network has the best coverage?
All mobile phone networks have great coverage in some areas and weaker coverage in others.
As more networks are building bases and putting up masts around the country, the mobile phone coverage in the UK is improving too.
There will still be areas where some networks have weaker mobile coverage, and each of the main networks provides a map on their site to show where their coverage is best.
Here we go through each of the major carriers and outline the sort of coverage and connection speeds you'll receive, as well as any perks and sweeteners you can expect for choosing that network.
EE mobile coverage
Formed out of the merger of Orange and T-Mobile, EE is now best-known for offering the UK's widest and fastest 4G coverage with "more masts than any other network". EE's premium 4G service offers speeds of up to 60Mbps.
At the time of writing, EE's network covers 73% of the UK population in 299 locations.
Unique selling points: As well as being the fastest network, EE offers some great incentives.
Not least, the EE Wednesdays promotion that entitles subscribers to two-for-one dining at Pizza Express and two-for-one cinema tickets.
Compare EE SIM only deals here: EE SIM only deals.
Compare all EE mobile deals at uSwitch now.
Three mobile coverage
Three's 3G network now covers more than 98% of the UK population, who can expect speeds of up to 21Mbps.
Work is ongoing to improve the infrastructure so it can offer Advanced 3G, which will enable customers to get speeds up to five times faster the UK 3G average for no extra charge. Advanced 3G is available to 80% of the UK population with Three.
Three also offers a 4G service and is aiming to roll this out to 50 cities by the end of 2014. By the end of 2015 it is aiming to offer 4G to 98% of the population.
Unique selling points: Choose Three and you won't get the range of sweeteners you get with O2 and EE.
But you do get a good service and cheaper price points, not least because Three customers who can get 4G pay no more for their super-fast service than 3G customers.
Compare Three SIM only deals here: Three SIM only deals.
Compare all Three mobile deals at uSwitch now.
O2 mobile coverage
O2 offers nearly 99% 3G coverage across the UK. Its 4G network is less extensive, but in early 2014 had reached 41% of the population.
Unique selling points: O2's suite of incentives have a strong claim on being the best around.
As well priority booking at O2 venues and offers at shops and on experiences, customers get free Wi-Fi in select locations via O2's hotspot network.
O2 pay as you go customers also get 10% of their top-ups back every three months.
Compare O2 SIM only deals here: O2 SIM only deals.
Compare all O2 mobile deals at uSwitch now.
Vodafone mobile phone coverage
Vodafone's 3G service is available to 80% of the UK and is capable of maximum connection speeds of 21Mbps.
In February 2014, Vodafone's 4G super-fast offering was less widely available, with 35% coverage. However, it has targeted 98% coverage across the UK by 2015.
Unique selling points: Vodafone customers on 4G Red plans qualify for 6 months free use of music streaming service Spotify or Sky Sports.
Compare Vodafone SIM only deals here: Vodafone SIM only deals.
Compare all Vodafone mobile deals at uSwitch now.
Tesco Mobile mobile phone coverage
Tesco Mobile offers speedy 4G and 3G, based on O2's network. That means that if you choose Tesco Mobile you'll get the same speeds and coverage.
Unique selling points Tesco Mobile's major selling point is that customers get Tesco Clubcard points for what they pay on their smartphone contracts.
Compare Tesco SIM only deals here: Tesco SIM only deals.
Compare all Tesco Mobile deals at uSwitch now.
GiffGaff mobile phone coverage
GiffGaff offers speedy connections at a good price. Like Tesco Mobile, it's based on O2's network and offers 3G and 4G coverage and speeds in line with O2.
Unique selling points: GiffGaff's big selling point is price, generous allowances for the money.
Customers also get to change their allowance from month to month so that it best suits their needs and can qualify for money off when they recommend GiffGaff to friends.
Compare GiffGaff SIM only deals here: GiffGaff SIM only deals.
Compare all GiffGaff Mobile deals at uSwitch now.
Talkmobile mobile phone coverage**
Talkmobile is another value network, but one that's based on Vodafone's network. For the kind of coverage and speeds you can expect, check our section on Vodafone's mobile phone coverage.
Unique selling points: Talkmobile is a no-frills network. But with 99.7% coverage, good speeds and great price points, there's much to recommend it. And that goes double if you're on a tight budget.
Compare Talkmobile SIM only deals here: Talkmobile SIM only deals.
Compare all Talkmobile deals at uSwitch now.
About mobile phone coverage
All mobile phones rely on signal from a mobile phone network.
Without a signal from the network, you cannot even make an emergency call, despite what various networks or handset guidebooks may tell you.
The strength or quality of the mobile coverage is largely determined by proximity to a mobile phone network tower.
However there are other factors that could affect the quality of your coverage.
Your mobile phone should tell you how good the network coverage is using a set of bars on the display screen; the signal strength will change as you move around with your mobile phone.
The best mobile phone coverage is generally in urban areas, although even really busy cities have 'dead zones' where there is no network coverage.
Mobile phone coverage 'dead zones' normally occur where signal between the mobile handset and the phone network cell antenna is blocked.
Mobile phone signal can be blocked by tunnels, hills or dense tall buildings.
Rural areas with a smaller population have less physical interference but often are too far away from a mast for good signal.
This is constantly improving as more and more antennas are put up around the country to improve UK coverage.