What cellular service to use when visiting the UK?

Many people come to the UK every year for business, for visiting their families or maybe just for fun. Irrespective of why you visit the UK, one of the things that may be on your mind is “how much will I pay for roaming?” or “how much would it cost me to make phone calls?” or maybe something along those lines. If you search online, you will find that the cost for 1GB of mobile data in the UK is between $6 and $7 (USD), which may be cheaper than countries like the US/Canada but still more expensive than some European and Asian countries. You may also find that the penetration of 4G in the UK is not as high as in some other countries, which could make you wonder, “why am I paying so much money when I am not even getting 4G?”. One key thing to remember is that just because you are getting 4G coverage in a country doesn’t necessarily mean that you will have great speeds also because it is always a combination of coverage and capacity that makes the difference.

Telecom UK holidays

If you are coming to the UK and want to stay connected, there are many great options. In fact, you can get so much data that you may even feel a bit ‘spoilt’. But for you to really enjoy the data freely, there are some key decisions for you to make, i.e. do you want to pay for roaming –OR– do you want to buy a local SIM in the UK for the duration of your trip. If your trip is longer than a few days and you don’t really know anyone who can lend you their spare tablet or any other SIM-enabled device as a mobile hotspot, then it might be worth considering a local SIM. That helps, especially if your trip involves many outdoor activities, so you can move around without having to worry about bill shocks or using unknown WiFi hotspots. But let’s clarify a few terminologies first to avoid confusion:

What is a local SIM?

If you buy your mobile service from the country where you live, then all the mobile services you use in that country will be charged at local rates, hence the term local SIM. As soon as you leave the country and go somewhere else, you will be charged at a higher rate because your mobile operator will have to pay extra money to mobile operators in the other country to keep you connected. Your mobile operator will recover that money by charging you the roaming fees applicable to the country you are visiting. In the olden days, there was something called “national roaming”, which was when a mobile operator did not have full coverage in the entire country and partnered with other mobile operators to keep their customers connected when they were visiting those uncovered areas. An inter-related term that can cause confusion is international calling. International calling is when you have a local SIM, and you use the SIM in your own country to make calls to other countries. In those situations, your mobile operator charges you international calling rates. You can check out our dedicated post on the comparison between roaming and international calling.

Example of roaming and international calling

If you live in the US and need to make a phone call to a UK number (e.g. +44 7xxxxxxxxx), your mobile operator in the US will charge you at international calling rates unless you have a special package from them that gives you international calling minutes. The same goes for sending SMS or MMS also. In the same example, if you visit the UK and decide to make a phone call to the same UK number, you will now be charged at roaming rates. Many mobile operators nowadays include roaming packages in their subscriptions that allow you to use your home allowance in other countries at specific rates for each country. Home allowance is the minutes, texts and data included in your normal mobile phone plan, e.g. Unlimited minutes & texts + 50 GB of data.

What solution would you need during your UK trip?

The kind of solution you need depends on what you want to do when you come to the UK. For example, if your trip requires making lots of local calls, e.g. to taxi drivers, friends & family or maybe joining audio conferences through local UK numbers, then it may be better for you to get a local UK SIM. While many local numbers are included in the mobile plans, you can still check the call rates on this page from Ofcom for numbers that may incur additional charges.

If your need is more around ‘local calls’ instead of ‘data’, then your best bet would be to get a tariff that gives you unlimited minutes/texts with a few GBs of data. On the other hand, if your main requirement is data, e.g. making WhatsApp calls, checking maps online, uploading photos on FB, then you can either get a regular SIM with a lot of data or get a data-only SIM to put in a tablet or MiFi device to have your own little hotspot wherever you go.

There may be cases when you feel that you need a local SIM, but you still need to make international calls back to your home country or other countries outside the UK. Interestingly, there are ‘international’ SIMs available from some UK mobile service providers to help you do just that. The UK mobile market is highly competitive, making it a bit difficult to choose sometimes due to the similarities in the bundle prices from various key providers. So, it would help if you planned well to choose a network operator that gives you the right bundles, but at the same time, you want to make sure that you have decent coverage from that operator in the areas you will be visiting. Here we have a simple step-by-step approach to help you:

Step Description
Step # 1Decide whether you want to avoid buying a new SIM and pay roaming charges to your mobile operator -OR-buy a new SIM from a UK mobile operator for the duration of your stay for a fixed price.
Step # 2If you decide to go for a local UK SIM, your best bet is a prepaid SIM known as Pay As You Go (PAYG) in the UK. The postpaid contracts are called pay-monthly and are more suited to those coming to the UK for the long term. Postpaid subscriptions require credit checks, whereas prepaid SIMs are super easy to buy from most newsagents or superstores (e.g. Tesco, Asda etc.)
Step # 3Irrespective of what people recommend, always check the network coverage in the areas that you will be visiting. In the UK, all mobile operators have a network coverage map on their website where you need to enter the postcode of the area you are visiting to find out how good or bad the coverage is in those areas. If you are visiting an area without much access to WiFi, look for an operator with a good 4G or 5G coverage in that area.
Step # 4Find a bundle that best suits your needs regarding mobile data, voice minutes and text messages. If you plan to make international calls, look for those international SIMs we talked about earlier.

What cell phone carriers are in UK?

In the United Kingdom, UK, there are four (4) mobile network operators or carriers:

  • Vodafone
  • EE
  • O2
  • Three

These companies own mobile network infrastructure including radio network, core network, transport network, service/other platforms and frequency spectrum to offer 2G GSM, 3G UMTS, 4G LTE and 5G NR services in the UK. In addition to these mobile network operators – MNOs, the UK also has a wide range of virtual network operators called the MVNOs (Mobile Virtual Network Operator). MVNOs make use of the radio network infrastructure of MNOs to offer their services. We have a detailed post on the difference between MNOs and MVNOs, but generally an MVNO buys excess capacity from MNOs to be able to offer deals that target various customer segments.

Which mobile service provider has the best coverage in the UK?

The four mobile network operators – MNOs in the UK i.e. EE, Vodafone, O2 and Three are very competitive in terms of their network coverage as well as prices. Generally, if you pick any one of them or any of the MVNOs that use their network, you should be in safe hands. The best way to make your decision is to know in advance what you mostly plan to use your mobile phone for? If you are someone who needs their phone mostly for data-centric things e.g. watching or uploading videos, social media, playing games etc. then you need a mobile network with a good 4G LTE coverage. If the operator also offers 5G (and you’ve got a 5G capable phone), that is a bonus. However if you are someone who mostly uses their phone for calls and messaging, then any service provider with good 3G/HSPA/HSPA+ coverage will do the job. Having said that, network coverage depends on your location which is why you should always check the coverage map of the mobile operator you are interested in. When you check the coverage map, be very clear in your search and check specifically for 3G, 4G and 5G to have all the necessary information before you make a decision. At a personal level, I have mostly enjoyed using Vodafone and EE, and the network experience with them has been good and reliable.

How do I buy a SIM card in the UK?

When you are buying a SIM card in the UK, your quickest option is a prepaid SIM which is commonly known as a Pay As You Go (PAYG) plan. You can get the prepaid SIM cards even at the airport. Alternativley, you can get them from most newsagents, mobile phone shops, convenience stores or superstores like Tesco, Asda etc. You can also buy prepaid SIM cards for most operators through Amazon.co.uk or directly from the operator’s website. When it comes to buying a postpaid SIM commonly known as a pay monthly SIM, things are not as easy because the operator will need to run a credit check to make sure you are eligible. If you are new to the UK, then it may take a while before you are eligible to get a postpaid SIM. However it is easier to get a rolling contract from an operator to start off with. Later, when you get a pay monthly subscription, you can port the number if you want to keep the same number.

Can I just buy a phone and put my SIM card in it?

If you buy an unlocked phone i.e. a phone that is not locked to a mobile operator (e.g. Vodafone, EE etc.), you should be able to buy a SIM card from any mobile operator and insert into the phone to get it working. This statement holds for GSM, UMTS, LTE and NR networks. If you have a phone that uses CDMA for 2G and 3G (e.g. IS-95 or CDMA2000), then replacing the SIM will replace the LTE (4G) part which is SIM-based. If you want to use that phone in the UK, and if the phone also supports GSM and UMTS (check on gsmarena.com), then by replacing the 4G SIM you should be able to access 2G GSM and 3G UMTS networks in the UK also.

Is 5G available in UK?

Yes. 5G was launched in the UK in 2019 and since then there have continuous network deployments. At the moment, most (if not all) 5G network deployments are non-standalone just like in most parts of the world. Have a look at our dedicated post on 5G speeds to check out the average download and upload speeds you can get with 5G in the UK.

Do data SIMs in the UK have a phone number?

All SIM cards including data SIMs even if they are eSIMs have a dedicated phone number. Every SIM also has a unique international identity called IMSI (International Mobile Subcriber Identity) which you can learn more about in our dedicated post on IMSI vs IMEI.


If you are visiting the UK for a short duration your best option may be to stick with your existing mobile operator and pay for roaming so that you can don’t have to carry two phones. However, if your trip is longer, or if you have a dual SIM phone, you may be better off buying a prepaid SIM from a local UK mobile service provider. The mobile network operators (MNO) in the UK are EE, Vodafone, O2 and Three. In addition, there are many MVNOs with their own SIM cards that use the mobile network of MNOs to offer their services.

Here are some helpful downloads

Thank you for reading this post, I hope it helped you in developing a better understanding of cellular networks. Sometimes, we need some extra support especially when preparing for a new job, or studying a new topic, or maybe just buying a new phone. Whatever you are trying to do, here are some downloads that can help you:

Students & fresh graduates: If you are just starting, the complexity of the cellular industry can be a bit overwhelming. But don’t worry, I have created this FREE ebook so you can familiarise yourself with the basics like 3G, 4G etc. As a next step, check out the latest edition of the same ebook with more details on 4G & 5G networks with diagrams. You can then read Mobile Networks Made Easy which explains the network nodes e.g. BTS, MSC, GGSN etc.

Professionals: If you are an experienced professional but new to mobile communications, it may seem hard to compete with someone who has a decade of experience in the cellular industry. But not everyone who works in this industry is always up to date on the bigger picture and the challenges considering how quickly the industry evolves. The bigger picture comes from experience which is why I’ve carefully put together a few slides to get you started in no time. So if work in sales, marketing, product, project or any other area of business where you need a high-level view, Introduction to Mobile Communications can give you a quick start. Also, here are some templates to help you prepare your own slides on product overview and product roadmap.

Scroll to Top