How many GB do I need for the UK? Guide by travel profile

If you already know that you'll need data and just need to decide on the size of the package, this guide is for you: how many GB you actually need for the UK depending on how you travel and how many days you stay. No theory: just numbers, profiles, and the warning that almost no one gives you before flying to London.

The number, straight to the point

For a 5-day getaway to London, 3 GB is enough for most people. For 10 days travelling around the country, 5 GB. If you work from your mobile or share a connection with your family, go up to 10 GB. Less than 15% of travellers need more than that.

That's the short answer, and the one I use when someone asks me on WhatsApp from the airport. The UK is, in fact, one of the destinations where the least data is consumed: there's decent Wi-Fi almost everywhere you sit, transport is paid with contactless (which doesn't consume data), and a good part of the day is spent inside museums, pubs, or the underground.

The classic mistake goes in the other direction. Many people buy 20 GB for a week "just in case", return home with 16 GB untouched, and don't get it back. Data packages expire: paying extra isn't an investment, it's wasted money. And the opposite mistake —running out on the second day— can be fixed in two minutes with a top-up, so the risk isn't symmetrical.

My criterion: calculate about 500-700 MB per day for a normal tourist and round up to the next package. If you're outside the average (recording video, uploading to the cloud, long video calls), multiply by two. In the following sections, I break down where these numbers come from so you don't believe them just because I say so.

Brexit warning: your Spanish tariff may or may not include the UK

This is the number one confusion for Spanish travellers, and I encounter it every week: since Brexit, the UK is no longer part of the EU's regulated roaming area. The European rule that allows you to use your data in France or Italy without paying extra no longer covers British territory. Period.

Now for the important nuance: several Spanish operators continue to include the UK in their "Europe zone" due to their own commercial policy, not because the law obliges them. And since it's their decision, each one does what they want and can change it whenever they want. As of this guide, the situation is more or less like this:

• Movistar keeps the UK within its Zone 1, with a roaming data cap lower than your national tariff.
• Vodafone has covered it through promotions with expiration dates, which need to be renewed or checked tariff by tariff.
• Orange removed it from the European zone and places it in a separate zone with daily or weekly paid bonuses.
• MVNOs (Digi, Pepephone, Finetwork, Lowi...) each go their own way, and some do not include it.

The only way to clear up any doubts is to log into your customer area or call your operator before flying and literally ask: "Is the UK included in my zone and with how many GB?". What a colleague tells you happened to them last year is not valid: they probably have a different tariff. And if the answer is that it's not included, you know why the alternatives I explain in my guide to internet in the UK exist, where I compare each option with its prices and its small print.

How much each activity consumes, in real MB

Before choosing a package, it's good to know what eats up your data. The usual surprise is that maps consume almost no data and video eats it all. These are the figures I use, rounded up so that your calculation has a margin:

Notice the pattern: anything that is text, maps, and messaging is pocket change; anything that is video shoots up the meter. If you're curious about the details app by app, I break it down in my article on mobile data usage statistics by activity. The practical conclusion is that your consumption in the UK will depend almost entirely on how much scrolling and how much video you do, not on how many kilometers you travel.

Why you'll spend less data in the UK than you think

There are destinations where your phone never rests. The UK is not one of them, and there are three specific reasons.

The first is Wi-Fi. In London, and generally in all British cities, free Wi-Fi is everywhere: pubs, coffee shop chains, museums (which are often free), public libraries, hotels, shopping centres, and a good portion of Tube and train stations, where you usually just need to register once. A day where you have breakfast in a cafe, lunch in a pub, and visit two museums is a day where half of your consumption is absorbed by an external network.

The second is language. It sounds silly, but it changes the number a lot. In Japan, Thailand, or Greece, you spend the trip with the translator camera open, pointing at menus and signs, and that consumes data. In the UK, you don't translate anything: you read the signs and that's it. You save hundreds of megabytes and a good deal of battery.

The third is contactless payment. On London transport, you tap your card or phone on the reader and that's it: Apple Pay and Google Pay work even if you don't have coverage at that moment, because validation doesn't need internet at the gate. There's no need to buy tickets via an app or load QR codes.

Add it all up and you have a data-cheap destination. That's why it annoys me to see people buying 20 GB packages for a week: in the UK, that's almost always paying for gigabytes that will go unused.

...and why London makes you spend more

That said, London has a particularity that pushes in the opposite direction: it's a city you travel with your phone in hand. It's not a capital where you "leave the hotel and walk to the main square." It's a huge city where every journey is decided on the screen.

Citymapper or Google Maps open to know which line to take, which metro exit to use, and if bus 24 arrives before the Northern line. Checking schedules, strike or line closure notices, tickets saved on your phone, restaurant reservations, the museum map. On a day in London, you open your phone forty times, even if each time it's only a few megabytes.

And then there's the underground. For years, the Tube was a black hole with no coverage, which paradoxically saved data. That's changing: around 60% of underground stations now have 4G and 5G on platforms and concourses, the most central lines also have signal inside the tunnels, and the Elizabeth line is covered end-to-end. TfL is working to complete the network. Practical translation: now you can scroll through Instagram between stops, and that's where the real expense goes.

My advice for London: budget a little more than for the rest of the country, around 700 MB per day if you're someone who looks at your phone in the carriage, and be aware that the connected underground is precisely where you're most likely to lose gigabytes.

Master table: GB by profile and by days

This is the table I show everyone who asks me. Find your profile, cross-reference with the number of travel days, and that's your number. It's calculated for a single mobile phone and assuming you'll sleep somewhere with Wi-Fi.

A couple of honest clarifications about this table. First: if you're in the first row —and most people travelling to London for four days are—, 3 GB will be more than enough even if the store has larger and more expensive packages. I say this knowing that we sell the larger ones.

Second: if there are two of you, it's not always worth sharing a large package via hotspot. Sharing consumes battery quickly, and the person acting as a modem will run out of phone by the afternoon. Two small packages are usually better, unless one of you barely uses the phone. If you want to fine-tune the calculation for any destination, I have a more general mental calculator in the guide on how much data you need to travel, which is the starting point for other countries.

3 to 5-day getaway: the real calculation, hour by hour

The short trip to London is the most typical trip Spaniards take to the UK: a cheap flight, Thursday to Sunday, three or four nights. Let's break down a full day so you can see where the numbers come from.

Multiply by the number of days and you have your figure: four days in London can be managed with 2-3 GB, with room for a silly day where you overdo it with reels. If your accommodation doesn't have Wi-Fi (rare, but it happens in some old hostels), add 40% more, because backups and series would then use mobile data.

A logistical note: remember that to enter the UK, Spanish citizens need an ETA, the electronic travel authorisation, and it must be processed from home before departure. It doesn't consume travel data, but it's good to have the proof downloaded on your mobile in case they ask for it at control, and downloaded means without needing a connection.

Road trip through Scotland or Cornwall: coverage and GB

Here the calculation changes in nature, and not in the way people expect. On a road trip through the Highlands, the North Coast 500, the Isle of Skye, the Lake District, or the coast of Cornwall, you will spend less data, simply because there are long stretches without coverage. You can't spend what you don't have.

The UK has very good 4G and 5G networks in cities and on main roads, but inland Scotland, the valleys of Wales, and some corners of Cornwall still have dead zones for miles. This means you have to change your preparation, not the size of the package:

• Download offline maps before you leave, and not just of the city: of the entire region. In Google Maps, you do this from your profile; in Apple Maps, from the app settings.
• Save accommodation reservations, ferry tickets, and entrance tickets in downloaded format, not in an email you have to open.
• Have your music and podcasts for the journey downloaded: in the car is when you spend the most time listening, and streaming really adds up.
• Tell people at home that you might be offline for hours. It's not the data package: it's Scotland.

With that, a 10-day road trip in the north can easily be done with 5 GB. Your budget will go on city days —Edinburgh, Glasgow, Bristol— and on hotel time at night, not on the road. If the trip mixes London and countryside, calculate each block separately and add them up, which is much more accurate than a general average.

How to check your own consumption before leaving home

Everything above is based on averages. Your real number is already in your pocket, and it takes two minutes to find it: look at how much mobile data you used last month and extrapolate. It's the most honest method I know, because it uses your data, not that of some invented average traveller.

On Android: Settings → Network & internet → SIM → Data usage. On iPhone: Settings → Mobile Data, and be careful, the counter there is cumulative since you last reset it; if you've never reset it, do so today and check it in a month, or look at the breakdown by app. You can also see it in your operator's app, which usually provides monthly consumption.

Now apply two corrections. Downward adjustment: at home and in the office you are almost always on Wi-Fi, so your mobile consumption already excludes a good part of your usage; in the UK, you will also have Wi-Fi at your accommodation. Upward adjustment: when traveling, you use maps all day and take four times as many photos. In practice, both tend to balance each other out quite well, so the table's result is usually very close to reality.

Tips for extending your data while traveling

If you've bought just enough—which is what I recommend—these tips will help you get to the end of your trip without any surprises. None of them take anything away from you; they just prevent unnecessary expenses.

• Download offline maps at the hotel. Save the initial map loading, which is the most foolish 50-100 MB of your trip.
• Backups only via Wi-Fi. Google Photos and iCloud are, by far, the biggest silent data hogs. Check this option before leaving home, not on the plane.
• Disable auto-play video on Instagram, TikTok, X, and Facebook. With just this, half an hour of scrolling goes from 400 MB to just over 100 MB.
• Activate data saver mode (Android: Data Saver; iPhone: Low Data Mode). This stops background updates.
• Video and music at medium quality. On a mobile screen, you won't notice the difference between 720p and 1080p, and consumption is halved.
• Download series and podcasts for the flight, the train to Edinburgh, and waiting times.
• Take advantage of pub and cafe Wi-Fi for heavy tasks: updating apps, uploading photos, long video calls.

A rule I always apply: heavy tasks via Wi-Fi; urgent tasks via data. If you follow this, a small package will yield twice what you expected.

There are more tips, including fine-tuning each operating system, in my compilation of tips for saving data while traveling. With two or three of them well applied, the difference between one package and the next stops mattering.

What happens if you run out (and why it's the best option)

Let's address the question that's really holding you back: what if I run out of data in the middle of my trip? Short answer: nothing happens. You run out of gigabytes, stop browsing, and recharge from your hotel's Wi-Fi or the first cafe you find. Five minutes and you're good to go. In the UK, with Wi-Fi on every corner, the risk of being truly out of communication is practically zero.

That's why asymmetry rules. Going over means paying for gigabytes that expire unused and don't come back. Running out means a quick recharge from a free network. Between an error that costs money for sure and one that costs five minutes, I always choose the latter.

A couple of precautions to make recharging painless:

• Activate consumption alerts in your phone settings at 70% of the package, so you're notified with plenty of notice.
• Save the recharge website to your favorites before traveling, so you don't have to search for it when you don't have a connection.
• Keep your purchase email handy: it contains your order number if you need support.

And if it's your first time with this technology and you're more concerned about the activation process than the gigabytes, in this guide I explain what an eSIM is step by step, without technical jargon. Installation is the least of it: you do it on your couch at home before flying, and then you just have to activate it when you land.

Frequently Asked Questions

The most common questions I receive about gigabytes and the UK, answered in two lines each.

Conclusion

If I had to summarize it in one sentence: the UK is a cheap data destination, and almost no one needs as much as they think. With 3 GB, you can manage a four or five-day trip to London; with 5 GB, you can spend ten days traveling around the country. Only if you work from your phone, share data with family, or constantly upload stories does it make sense to go for 10 or 20 GB.

Remember the two things that really matter here. One: check with your operator if your plan includes the UK, because after Brexit it is no longer guaranteed by law, and that two-minute call will save you trouble with your bill. Two: buy just enough and recharge if necessary, because unused gigabytes don't come back.

Once you're clear on that, choosing the package is easy: you can see the sizes and prices of the eSIM for the UK and activate it before leaving home, so you land at Heathrow or Gatwick with internet working from the first minute. And if you want the complete context of coverage, operators, and practical tips for the country, you can find it in the UK eSIM guide.

Written by Marc González Sáez Founder of PuraSim and a specialist in eSIM and connectivity for travelers. He has been helping people travel connected worldwide for years without overpaying for roaming, and personally tests eSIMs in each destination before recommending them.