Searching for a good mobile network to join, that performs well in London?
In this guide, we’ve taken a look at which mobile networks are best in London – in terms of coverage, speeds, value for money, and more.
Let’s get started.
Best mobile networks in London
Below, we’ve ranked the top five mobile carriers in London at the moment.
The information below is based on our real-world testing of each mobile network in the city, performing a number of speed tests in different areas using two different Android phones.
1. Three
Each quarter, Ookla, the company that runs speedtest.net, releases a report ranking the speeds of UK mobile networks, based on user speed tests.
According to their data, Three is the fastest mobile network in London at the moment.
And from testing we’ve performed, they are almost always faster than Vodafone, EE and O2 in most areas of London.
They include unrestricted 5G speeds by default on all of their plans, and are generally very cost-competitive, compared to the other big four networks.
The main downside to Three is their roaming allowances aren’t the best. You’re limited to using just 12GB of your data limit overseas each month, and only in certain European destinations.
However, in terms of 5G speeds and coverage, Three is hard to beat – and they also perform well on 4G as well.
2. Smarty
Smarty is a smaller provider that uses the Three network, but offers simpler plans, with cheaper prices.
They still offer fast, unrestricted 5G, and from our testing, deliver the same speeds and coverage as their parent network, potentially because Smarty is directly owned by Three, rather than just leasing access from them.
We’ve actually seen instances where Smarty offers faster speeds than Three, such as this test taken on two different phones at the same time, in an area with weak 5G signal.
In general though, they perform about the same when it comes to download and upload speeds, and both offer good call quality throughout London as well.
This network doesn’t have the same range of pay monthly phone plans as Three, but they have a great choice of flexible SIM-only deals, making them a good option if you already own your phone outright, and don’t want to enter into a long-term contract.
Similar to Three though, Smarty’s roaming allowances aren’t that generous. But WiFi calling is included, which is good to see from a small network.
On the whole, if you’re looking for ultrafast 5G in London for the lowest possible price, Smarty is definitely worth looking at.
3. VOXI
Vodafone offers the second-fastest average speeds in London. But buying from Vodafone itself can be very expensive.
So, instead, if you want a pay as you go SIM, their sub-network, VOXI, might be worth looking at.
VOXI is very price-competitive, and offers a great range of SIM-only deals. They also exclude certain social media and video streaming apps from your data usage limit, on some of their plans, which can be very useful if you have a tariff with a small allowance.
And since they’re on the Vodafone network, VOXI has really good speeds and coverage in London.
However, it is worth noting, their speeds aren’t completely unrestricted, like they are with Three. So, in the city centre, you might not get quite as good download speeds as you would with Three, or Smarty.
4. EE
If you ever struggle with poor mobile signal in certain parts of London, EE is worth looking at.
They’re not the cheapest mobile network on the market, nor do they offer the fastest 5G speeds.
In fact, many of their plans are speed-capped, unless you pay more for an unrestricted tariff.
However, EE has the best coverage of any mobile network in the UK right now, including in London.
Their 4G coverage is particularly impressive, and they are currently deploying ultrafast standalone 5G in London, although most of their users are on cheaper, speed-restricted plans.
Even on 4G LTE, EE still offers very fast speeds compared to most other networks.
Therefore, if you don’t mind paying a bit more than you would with some other providers, EE can be a great way to get stable speeds, with no call dropouts, basically everywhere in London.
5. Lebara
Similar to VOXI, Lebara is another mobile virtual network operator (MVNO) that uses Vodafone masts, meaning they offer really good coverage and speeds in Greater London.
They’re extremely price competitive, offering cheap pay as you go plans, and you can save even more money by committing to a 12 month tariff instead, if you’d prefer.
Another unique thing about Lebara is their SIMs include 100 international minutes per month to about 50 different countries, which is quite rare to see. Most SIM-only plans only come with UK calls and texts at the moment.
Of course, you can still make unlimited international calls using apps like WhatsApp instead, if this is more convenient for you.
Continuing the international theme, Lebara has quite a good 30GB free roaming allowance, and their roaming plans cover destinations beyond the EU, including India and China.
What you need to know
In this section, we’ve explained some important things to consider when changing mobile networks in London.
Which network has the fastest speeds in London?
According to data from speedtest.net, Three is the fastest mobile network in the UK at the moment, in terms of average real-world 5G download speeds.
Vodafone ranks in second place, followed by EE, then O2.
These numbers are roughly backed up from our testing, although we think EE is faster than Vodafone, if you compare tariffs with unrestricted speeds.
In terms of 4G, it’s a bit closer between the big four networks. In areas with good signal, they will all top out at around 100 Mbps.
However, EE and Three tend to have the best 4G speeds in London right now. We have seen particularly good performance from EE in certain areas.
Which is the cheapest mobile network?
The cheapest mobile network in the UK can vary over time.
Therefore, we recommend checking our SIM-only deals comparison page to see which is the cheapest when you’re reading this, given how much monthly data you need.
You can also compare pay monthly smartphone deals on our website as well.
In general, smaller, mobile network virtual operators (MVNOs) like Smarty, VOXI, and giffgaff tend to offer the cheapest prices on SIM-only deals.
Which network has the best coverage in London?
In the city centre, most mobile networks have good coverage, especially outdoors.
The performance of each network often depends on how congested a given area is.
This is why, given how fast their real-world speed test results are, we think Three is often a great choice in London.
However, in certain parts of Greater London, 5G isn’t readily available, so the level of 4G coverage is what matters most.
And in terms of 4G, EE has the most widely available network in London, and the best coverage for calls, although they are a bit expensive.
How to tell how good a network is in your area of London
Before buying a new SIM plan, it’s a good idea to check and see how that network performs in your borough, or on your street, to ensure you’ll get good speeds and signal.
There are a few different ways of doing this.
- Use the network coverage map. If you click on “More Details” under a given plan when comparing phone deals on our comparison site, you’ll see a link to the network’s coverage map. Put in your postcode, and look for 4G or 5G signal at home, at work, and anywhere else you frequently travel.
- Perform speed tests using a friend or family member’s phone. This can be a good way to assess real-world performance in an exact location.
- Test out the network on a cheap, pay as you go SIM-only plan. Fortunately, with most mobile networks, it’s easy to sign up for a SIM, test it over the course of a week or so, and cancel it if necessary. You can begin with a small data limit, and upgrade to a larger allowance if the network performs well from your testing.
Will my 4G/5G be any good on the Tube?
Currently, TfL is rolling out 4G and 5G connectivity throughout the London Underground network.
So far, about 65 stations have mobile connectivity, as well as about 40% of lines on the network.
This means, whether you get good 4G or 5G on the Tube depends on what line you’re travelling on, or which stations you’re visiting – and it can be a bit hit or miss.
If you’d like to prioritise rail connectivity when choosing a mobile network, EE is generally the best choice, thanks to the level of investment they’ve made into their 4G coverage in London and the broader UK.
How much should I expect to pay for a mobile plan in London?
Fortunately, mobile plans tend to be relatively cheap in the UK.
You can expect to pay as little as £7-£10 per month for a SIM-only tariff with an MVNO, or maybe a bit more if you choose one of the big four networks, especially Vodafone or EE.
Unlimited data plans, or plans with unrestricted speeds on speed-restricted networks, often cost a fair bit more than this – more in the region of £20 per month.
If you need a phone as well as a data plan, this can cost anything from £20 to £60 per month, depending on the phone and the network you choose.
You can compare handset and SIM-only deals on the main section of our website.
How to keep your mobile number when changing mobile networks
Fortunately, it’s very easy to keep your phone number when switching mobile networks.
Here’s what you need to do.
- Using your current SIM, text “PAC” to 65075.
- You’ll receive a Porting Authorisation Code (PAC) from your current mobile network operator.
- Supply the PAC to your new network when activating your SIM – you can also do this later on, after purchasing and setting up the SIM, if you want.
Once that’s done, you’ll be able to make and receive calls, and send and receive texts, using your current mobile number on your new phone plan.
Conclusion
You’ve reached the end of our guide to the best mobile networks in London.
Essentially, Three is a great choice if you want the fastest possible speeds, and have a 5G-compatible phone.
But if you want to save money, Smarty or VOXI might be a better choice.
If you’re still not sure which network to pick, leave us a comment below, and we’ll get back to you as soon as we can.
About the author
Tom is the founder of Green Smartphones. You’ll find him writing about phones on the Green Smartphones blog, or talking about SIM deals and mobile networks on our YouTube channel. He’s the Android expert on the team – currently using a Google Pixel 9, recently upgrading from a very long-suffering Note 20 Ultra. When he’s not working on Green Smartphones, you’ll find him playing football or hiking.