If you're thinking of buying an iPhone on contract, you've got a SIM-free iPhone and want to sign up to a contract, or are nearing the end of a contract and want to go with a different provider, you'll be wanting to know which network is best for you. This article is the right place for you.

We go through the various network providers available in the UK and discuss their pros, cons and general performance. For more general network comparisons have a look at The best phone network in the UK by our colleagues on Tech Advisor, and see Best iPhone deals for the latest contract offers at the lowest prices.

What networks are there?

In the UK we have four big networks:

There are many further providers, but they all 'piggyback' on the infrastructure of one of the above. So EE is piggybacked by BT Mobile, Plusnet and Virgin Mobile; O2 is piggybacked by Giffgaff, Tesco Mobile and Sky Mobile; Three is piggybacked by iD Mobile; and Vodafone is piggybacked by Talk Mobile.

This piggybacking arrangement will be relevant when we discuss coverage, speed and reliability because the smaller providers are reliant on the physical infrastructure of their chosen big network, and will be susceptible to the same problems.

What do you need from your network?

When selecting a network there are lots of different criteria to consider. You will probably have to compromise in one area to get what you're looking for in another.

Price

For a rough comparison of prices, in the individual entries below we've listed the lowest monthly fee each network offers (at time of writing) for the iPhone XR, over 24 months and with a maximum upfront cost of £100 and a minimum of 1GB data. Check the individual sites for up-to-date prices.

When looking at pricing it's important to look at total cost of ownership (TCO) over the course of a contract, which includes the upfront cost and however many monthly payments are required. An apparently unappealing contract may work out the best for you if it only lasts 12 months (most are 24 or more).

Carphone Warehouse's contract comparison tool can show TCO but doesn't by default. Put a tick next to 'Show total cost of ownership' in the lefthand bar. Individual network sites probably won't list TCO, and you'll have to work them out for yourself.

Best iPhone network: Show total cost of ownership

The amount you pay will vary according to your monthly data allowance, the value of the phone (assuming it's included) and any additional features, such as Apple Music subscriptions. But beyond this, some deals are simply better value than others. You shouldn't assume that you're paying a fair price.

Coverage

Most of the UK now has decent 3G coverage, and quite a lot of it has 4G. But there still remain rural pockets with nothing at all.

If you live in central London and don't plan to leave any time soon then you don't need to worry about coverage. But everyone else should at least consider it. Your choice of network will dictate what infrastructure you'll be using, and the location of your network's towers (or the towers belonging to the network your provider is piggybacking) will dictate how good a signal you can get in a given area.

Ofcom's mobile coverage checker is a useful tool for seeing which networks can cover your area - or an area you want to visit regularly.

According to the research firm RootMetrics, EE offers the best 4G coverage across the UK as a whole. Second place depends where you live: Vodafone was runner-up in England and Wales, whereas O2 was runner-up in Northern Ireland and Scotland.

(RootMetrics' coverage map is another useful tool for analysing likely performance in your local area.)

Speed

Whereas broadband deals trumpet their estimated speed from the rooftops, mobile networks are less public about the 4G speeds you should expect. But while the numbers can be hard to uncover - and, to be fair, lots of factors influence the speed you actually experience - it's clearly an important factor to consider.

To see how well your current provider is living up to their claims, you can use the free iPhone app Speedtest by Ookla. And the company uses these results to provide insights into the market as a whole: in its 2015 awards (sadly the most recent available) Speedtest reported that EE offered far and away the fastest 4G speeds across the UK.

And EE came top in a more recent report by Opensignal, winning the 2018 awards for 4G, 3G and overall speed across the UK.

Good news for EE, of course, but also good for the providers that piggyback on that company's infrastructure: BT Mobile, Plusnet and Virgin Mobile.

Reliability

Network outages are hugely frustrating, leaving you unable to access any online services until you get back to Wi-Fi. In Dec 2018, for instance, O2 customers were disconnected for a whole day.

This is another case where piggybacking is important. The above incident affected O2 piggybackers too - so when considering a network provider, check out reports of its parent network's reliability.

Customer service

This is where the smaller providers can stand apart from their parent networks. How efficient is the provider at dealing with problems, and does it offer compensation when things go wrong? Does it spam you with marketing letters? Does it get your bills wrong on a regular basis?

For an analysis of these elements we turn to Which?'s 2018 mobile customer satisfaction survey, which put Vodafone and EE bottom and second-bottom respectively.

Data limit

You can pay less if you're willing to compromise on your data allowance: contracts can vary from around 250MB to 60GB or more.

We'd advise against going for the real bargain-basement allowances: 2GB is probably a sensible minimum to aim for. But it all depends on what you're going to be using your phone for: streaming is a particular drain.

To get an idea of your requirements, read How much data do I need? And to read about ways you can reduce the amount you burn through, see How to save data on iPhone.

Can you sign up with more than one network?

Yes, if you've got a new enough iPhone. The XR, XS and XS Max all offer eSIM support, which means you can have a conventional hardware SIM from one network and an eSIM from another - but note that in the UK, only EE supports eSIM.

For more details, read How to use dual SIMs on iPhone.

1. Plusnet

Plusnet

Plusnet doesn't sell phones, but its prices on SIM deals are appealing if you bought an iPhone SIM-free. We like the ability to set a monthly price cap to prevent nasty surprises when your bill arrives.

Network: EE (piggyback)

Price: The cheapest you can currently go is £6 per month (which gets you just 500MB, 250 minutes and 500 texts) but we'd advise picking something a little more comprehensive - and bear that in mind that the other deals here include the handset.

Coverage: EE's network came out top for 4G coverage in England, Wales, Scotland and Northern Ireland in RootMetrics report. Also rated top for 4G availability by Opensignal overall and for every region. Just remember to check Ofcom's coverage tool to see how EE performs in your location.

Speed: Excellent, thanks to the performance of EE's network. It was rated top in Speedtest's 2015 report and wiped the floor with all of its rivals in Opensignal's 2018 survey.

Customer service: Decent. Plusnet got a score of 4/5 for customer service in Which?'s survey, and the same for ease of contacting. Its overall customer score, 65%, put it in 6th place out of 13.

Read more on Plusnet's website.

2. Virgin Mobile

Virgin Mobile

Going with Virgin Mobile makes sense if the firm already provides your broadband and TV. We also like its data rollover features and option to change your 4G plan every month.

Network: EE (piggyback)

Price: Virgin has the iPhone XR for £42 per month (that's on 24-month contract; the site selects 36 by default) with no upfront payment, 1GB of data and 1000 minutes.

Coverage: EE's network came out top for 4G coverage in England, Wales, Scotland and Northern Ireland in RootMetrics report. Also rated top for 4G availability by Opensignal overall and for every region.

Speed: Excellent. EE, which provides the network infrastructure that Virgin relies on, came top in Speedtest's 2015 report and Opensignal's 2018 survey.

Customer service: Virgin got 3/5 for customer service and ease of contacting in Which?'s 2018 survey. Its overall customer score was only 58%, however, putting it in 11th place out of 13.

Find out more on Virgin Mobile's website.

3. BT Mobile

BT Mobile

BT Mobile is a sensible option if you subscribe to BT Broadband.

Network: EE (piggyback)

Price: BT offers the iPhone XR for £57 per month, which is unusually high. But you'll get £5 per month knocked off if you're a BT Broadband subscriber and, at time of writing, BT was temporarily offering the same deal for only £31 a month (or £26 if you use BT Broadband). Check for the latest deals.

Coverage: EE's network came out top for 4G coverage in England, Wales, Scotland and Northern Ireland in RootMetrics report. Also rated top for 4G availability by Opensignal overall and for every region.

Speed: Excellent. BT uses EE's network, and EE came top in Speedtest's 2015 report, and cleaned up virtually all the national awards in Opensignal's 2018 survey.

Customer service: Which? gave BT Mobile a score of 3/5 for customer service. Its overall customer score of 62% put it down in 9th place, out of 13 providers.

Find out more on BT's website.

4. EE

EE

EE offers excellent coverage and six months of Apple Music for free. It's a solid choice.

Network: EE

Price: EE offers the iPhone XR for £48 per month with 4GB of data and £29.99 upfront. EE has the XR for £43 per month on Mobile Phones Direct (£49 upfront, 30GB data).

Coverage: EE's network came out top for 4G coverage in England, Wales, Scotland and Northern Ireland in RootMetrics report. Also rated top for 4G availability by Opensignal overall and for every region.

Speed: Excellent. EE came top in Speedtest's 2015 report, and cleaned up in Opensignal's 2018 survey.

Customer service: EE scored 3/5 for customer service in the Which? customer survey, 3/5 for ease of contacting and an overall customer score of just 56% - putting it second from bottom in the table.

Visit EE's website for more information.

5. Tesco Mobile

Tesco Mobile

You could do a lot worse: Tesco Mobile offers a variety of deals at decent prices, with SIM-only a highlight.

Network: O2 (piggyback)

Price: At time of writing Tesco does the iPhone XR for a reasonable £44.74 per month plus £60 upfront, on a 24-month contract with 2GB of data, 5000 minutes and 5000 texts.

Coverage: O2's network was rated second best for 4G coverage in Scotland and Northern Ireland; third in England and Wales. Opensignal gave creditable mentions for 4G availability in Scotland, Wales, Northern Ireland and the North of England. O2 also won Uswitch's Best Network Coverage award for 2019.

Speed: Tesco suffers here because of its dependence on O2's infrastructure. O2 came bottom in Speedtest's 2015 report, and picked up zero awards in OpenSignal's 2018 report.

Customer service: Pretty good. Tesco got a score of 4/5 for customer service, and the same for ease of contacting, in Which?'s 2018 survey. Its overall customer score of 75% put it in 5th place, out of 13.

Find out more on Tesco's website.

6. Sky Mobile

Sky Mobile

As is the case with several of the firms in this article, Sky offers preferential mobile rates for those who subscribe to other Sky services.

Network: O2 (piggyback)

Price: Sky has the iPhone XR for £33 per month, with 1GB of data and no upfront cost.

That sounds terrific, but you're more locked in than with the other deals discussed in this article. Sky calls the arrangement Swap24, which means you get a new device after two years and then carry on paying for that; if you want to keep the original device your payments will drop, but you must keep paying until the full cost is paid off. Read about this setup here.

Coverage: O2's network was rated second best for 4G coverage in Scotland and Northern Ireland; third in England and Wales. Opensignal gave creditable mentions for 4G availability in Scotland, Wales, Northern Ireland and the North of England. O2 also won Uswitch's Best Network Coverage award for 2019.

Speed: O2, whose network Sky piggybacks, came bottom in Speedtest's 2015 report. It didn't get any speed awards in OpenSignal's 2018 report, either.

Customer service: Sky won the Best Network for Customer Service from uSwitch in 2019, and scored 4/5 for both customer service and ease of contacting in Which?'s 2018 survey.

Find out more on Sky Mobile's website.

7. O2

O2

One of the best-known and oldest operators in the market. O2 offers good coverage and some decent prices but speed may be a concern. 

Network: O2

Price: O2's best offer for the iPhone XR is £45 per month. (With 2GB of data and £49.99 upfront.) It's £41 a month on Mobile Phones Direct, with £75 upfront and a stonking 50GB data.

Coverage: O2's network was rated second best for 4G coverage in Scotland and Northern Ireland by RootMetrics; third in England and Wales. Opensignal gave creditable mentions for 4G availability in Scotland, Wales, Northern Ireland and the North of England. O2 also won Uswitch's Best Network Coverage award for 2019.

Speed: Not good. O2 came bottom in Speedtest's 2015 report, and collected no awards in OpenSignal's 2018 report. Nor did it receive any creditable mentions in terms of regional speeds.

Customer service: O2 scored 3/5 for both customer service and ease of contacting in Which?'s survey. Its overall customer score was a lowly 61%, putting it in 10th place out of 13.

Find out more on O2's website.

8. iD Mobile

iD Mobile

iD is Carphone Warehouse's inhouse network. It offers some excellent prices but nationwide coverage is not good (although your area may be fine - check Ofcom's tool) and speeds are middling. 

Network: Three (piggyback)

Price: iD offers the iPhone XR for £39.99 per month. (With 5GB of data and £49.99 upfront.)

Coverage: Three's network was rated bottom for 4G coverage in all four regions of the UK. Not mentioned in Opensignal's report.

Speed: As a Three piggybacker, iD doesn't get great speed numbers. Three's network came third out of four in Speedtest's 2015 report.

Three also failed to pick up any overall awards in Opensignal's 2018 report, although it got some positive mentions for 4G download speeds in Wales, Northern Ireland and the North East of England.

Customer service: iD got 3/5 in Which?'s 2018 customer survey, and a customer score of 63%, putting it in 8th place out of 13 - lowish mid-table performance, in other words.

Find out more on iD's website.

9. Vodafone

Vodafone

Vodafone has some decent deals on offer; we also like its Global Roaming option, which effectively extends your normal data plan to 152 overseas destinations. Speed and coverage are fine (if you're in one of the lucky 19 cities you can look forward to 5G) but there are some questions over customer service. 

Network: Vodafone

Price: Vodafone's lowest monthly charge for the iPhone XR is £46 per month on Carphone Warehouse. (With 5GB of data and £79.99 upfront.) You can get it for £42 a month on Mobile Phones Direct, with 30GB data and no upfront charge.

Coverage: Vodafone's network rated second best for 4G coverage in England and Wales; third in Scotland and Northern Ireland. Received no mentions for 4G availability in Opensignal report.

Speed: Not bad. Vodafone came second out of four in Speedtest's 2015 report, and while it dropped to third out of four in Opensignal's 2018 4G speed table, it was the only non-EE network to pick up any awards at all in that report (it excels at 3G and 4G latency).

Vodafone's speeds were found to be excellent in Wales.

Customer service: Vodafone performed badly in Which?'s 2018 survey, finished bottom of the table. It scored 2/5 for customer service and 2/5 for ease of contacting, with an overall customer score of 49%.

Find out more on Vodafone's website.

10. Giffgaff

Giffgaff

A small but popular operator, Giffgaff is highly rated by its customers. It's an O2 piggybacker, though, which puts a question mark over speeds. 

Network: O2 (piggyback)

Price: Giffgaff does the iPhone XR for £44.95 a month, which includes the minimum 3GB of data (which the firm calls a 'goodybag') and an upfront payment of £35.

Coverage: O2's network was rated second best for 4G coverage in Scotland and Northern Ireland by RootMetrics; third in England and Wales. Opensignal gave creditable mentions for 4G availability in Scotland, Wales, Northern Ireland and the North of England. O2 also won Uswitch's Best Network Coverage award for 2019.

Speed: Bad news for Giffgaff users: the provider piggybacks on O2's network, and O2 came bottom in Speedtest's 2015 report.

In OpenSignal's 2018 report, O2 collected no awards; nor did it receive any creditable mentions in terms of regional speeds.

Customer service: Giffgaff was awarded 3/5 for customer service in Which?'s 2018 survey. Taking into account the pricing and incentives offered by the network, it got an overall customer score of 81%, putting it 2nd out of 13.

Go to Giffgaff's website for more details.

11. Three

Three

Three's unlimited data bundles are an appealing prospect, although they're likely to cost you. Coverage may be a worry, so check your local area.

Network: Three

Price: Three has the iPhone XR for just £42 per month, but that's with only 500MB of data and 300 minutes (and £49 upfront). The £43 option (1GB data, unlimited minutes) is perhaps a more practical option.

Coverage: Three's network was rated bottom for 4G coverage in all four regions of the UK. Not mentioned in Opensignal's report.

Speed: Three's network came third out of four in Speedtest's 2015 report.

Three also failed to pick up any overall awards in Opensignal's 2018 report, although it got some positive mentions for 4G download speeds in Wales, Northern Ireland and the North East of England.

Customer service: Middling. Three scored an appropriate 3/5 for customer service and ease of contacting in the Which? 2018 survey. Its overall customer score of 64% put it in 7th place out of 13 - exactly halfway down the table.

More details can be found on Three's website.