Every megabyte counts: roaming vs travel eSIM

When your connection depends on roaming, you can’t see your data draining away, you don’t know the final total in advance, and you hit your limit precisely when you need the internet most.

More and more Britons are getting around this by setting up a travel eSIM service before they leave home — from the Swiss company Yesim, for example. It gives you a straightforward data package with a price and an allowance you know in advance, and it switches on within seconds of landing. Before we get into the details, though, it’s worth working out where your megabytes actually go on a trip, and why roaming turns that into a problem.

Where your megabytes go when you travel

On a trip every megabyte counts, especially when you’re paying roaming rates for it. Here’s how much data the popular apps and tools we’re all so used to relying on while travelling get through:

Google Maps services are the most economical thing on the list, getting through around 3–5 MB per hour of ordinary navigation. Outside the city you can drive around all day and still use less than 50 MB. There’s a catch, though: satellite mode or 3D view together push that up to 15–30 MB an hour and beyond. And abroad the consumption often doubles (10–30 MB an hour), because your phone is loading unfamiliar sections of the map for the first time.

Messengers such as WhatsApp are almost weightless — a quiet text conversation costs just 5–10 MB an hour, and once you add voice notes and photos, up to 30–50 MB an hour.

AI assistants — ChatGPT, Gemini, Claude. They’re handy for asking about a route or reading through reviews. If you type and stick to text, it costs next to nothing: around 1–5 MB an hour. Voice mode is another matter entirely, using dozens of times more data, roughly 1–2 MB a minute (that is, 60–120 MB an hour).

A video call home over WhatsApp or FaceTime is where the drain really starts to make itself felt. That’s about 5–15 MB a minute, or roughly 200–400 MB an hour. A single long evening catch-up with the family can easily come to hundreds of megabytes.

Instagram and other social networks — around 100–200 MB an hour for simply scrolling the feed, but switch to stories and it’s already 300–500 MB an hour, while reels and video can drive it up to 1 GB an hour.

Posting your own photos and stories is fairly light in itself. A single photo is 1–5 MB, or 10–20 MB at high quality. An hour of uploading and watching video stories, on the other hand, can come to 150–300 MB.

TikTok is one of the biggest data guzzlers on the entire list: 500 MB to 1.2 GB an hour.

Streaming video on YouTube or Netflix runs from 500 MB to 1–2 GB an hour even at standard quality, and in HD it’s several gigabytes an hour.

Why roaming is a financial trap

Roaming doesn’t just make all of this expensive. There are three specific reasons why it’s no longer a workable model.

The first is that you can’t see what you’re spending until it’s too late. Data leaks away in the background, and the final figure often only becomes clear once you’re back home. Plenty of British tourists have no idea that their operator charges separately for calls, messages and internet abroad, on top of their home plan. And other travellers never check roaming rates before a trip at all.

The second is that the allowance included in your plan can run out faster than you’d counted on, especially if you settle into a video call or scroll through reels for an hour. Buying more has to be done once you’re there, and it’s usually pricier — at separate roaming rates rather than domestic ones.

The third is that the price depends on exactly where you are, yet most people only find that out on arrival. Roaming carves the world up into zones, and it’s rarely obvious in advance which one your particular country falls into. Spain or Greece is one thing; Egypt, Morocco or India is a completely different and far more expensive zone.

All three of these traps can be avoided. A travel eSIM gives you a known amount of data at a fixed price.

How an eSIM differs from a travel eSIM

An eSIM is simply a built-in chip, found in every iPhone from the XS onwards, in every Google Pixel, in recent Samsung and Motorola models, and in most current mid-range and higher Android phones. It lets you load an operator profile remotely, with no trip to a phone shop.

A travel eSIM is the service that uses that chip: an app, a range of plans, technical support and the ability to manage data across several devices at once.

How a travel eSIM removes the roaming traps: Yesim as an example

Yesim is a Swiss company founded by specialists from telecoms and IT. It has been working in the travel eSIM market since 2019. Today more than 4 million people use the service across over 200 destinations.

You set your connection up in advance, before you even fly. To do that you check that your phone is compatible, install the Yesim app and load the profile — nothing complicated, as the app talks you through every step. Once you land you activate the travel eSIM, which takes a matter of seconds.

The price and the amount of data are known upfront. You buy a specific package — unlimited data for a fortnight, say — at a price locked in before departure. Yesim covers most types of trip, incidentally: there are plans by country, by region and even by city. And there are global ones — the Global Package covers over 80 countries, the Global Plus Package more than 140. You can also choose the Pay & Fly plan, where you only pay for the data you’ve actually used (the price per gigabyte is known in advance).

With Yesim you can also test the quality of the connection without committing to anything. A 500 MB trial package costs around £0.45 — enough to form an impression of the service without spending a large sum.

Your connection stays under your control the whole time. You switch the eSIM on yourself when you need it, and throughout the trip the app shows you how much data is left.

On top of all that, you get a reliable connection. Thanks to SwitchLess Networks technology, your smartphone automatically connects to the strongest of more than 800 partner networks. That’s a particular help in a remote location, or somewhere thousands of people need a signal at the same time — at a concert, for instance.

Important calls and messages won’t get lost either. Your British number stays active throughout: the eSIM handles the internet only, so bank codes and incoming calls still reach you as usual.

For families and groups of friends there’s the Multiple eSIMs feature: from a single account you can manage several profiles at once and share them with other users, even if they don’t have the app installed on their phone.

New users are entitled to a 15% discount with the promo code GETYESIM15.

The company’s international standing is also reflected in its recent partnership with the World Players Super League — the world’s largest golf tour, which runs more than 1,800 tournaments a year across over 50 countries and reaches a combined audience of more than 7.5 million people.

Conclusion

Megabytes really do matter on a trip — the only question is who counts them, and how. With roaming, the operator does the counting: after the fact, by its own zones and its own rules, and you often only see the total once the trip is over.

With a travel eSIM you count for yourself: an allowance chosen in advance at a price known in advance, with nothing left to guess at. For anyone heading abroad the choice is fairly simple — a travel eSIM package bought beforehand instead of an anxiety inducing meter ticking away in your head.