Travel eSIMs: your biggest questions, answered.
If you’ve sat the night before a flight typing in ‘what is an eSIM’ or as you’re in arrivals clicking on multiple articles to try to find the best one to answer, ‘is my phone eSIM compatible’ or ‘will an eSIM work in this country’, then you’re not alone.
More and more people are ditching the physical SIM kiosks at airports and the heavy roaming charges on home networks for a simple QR code and a few taps to connect via an eSIM. However, as simple as it sounds, it’s not to say it doesn’t come loaded with questions.
So, we pulled together some of the most asked questions for not only before buying an eSIM but also during and after, providing you with the ultimate guide to staying connected with no jargon and, more importantly, no fluff.
The basics
1What is an eSIM, and how is it different from a physical SIM?
An eSIM translates to an embedded SIM, meaning it is quite literally built into your phone’s hardware with no need to place the physical plastic chip into your phone. Instead, you download a small profile, usually via QR code and then your phone activates it like a normal SIM.
Functionally, an eSIM does the exact same job as a physical SIM, connecting you to a mobile network. The only difference is that there is no small plastic chip you need to fiddle around with or risk losing.
2Is my phone eSIM compatible?
Most phones made in the last four or five years are eSIM compatible – think iPhone XS and onward, Google Pixel 3 and most Samsung Galaxy S and Note models from the S20 era onward.
An easy way to check is to go into your phone’s settings and go:
It is worth noting that some carrier-locked phones or region-specific models (explained below) have eSIM disabled even if your hardware supports it.
3How do I install and activate a travel eSIM?
The process is usually identical across all eSIM providers.
The whole process takes nothing but a few minutes – more importantly, it can all be done before you leave the comfort of your own home.
Timings and logistics
4When does the eSIM validity actually start?
This question trips more people up than anything else on the list, and the answer is simple. The validity countdown begins when the eSIM connects to a network for the first time, i.e. when you land in Spain for your holiday, it is only then that the countdown begins, not when you purchased it.
This means you can buy your eSIM even weeks before (and up to 6 months at Mozillion) and it won’t start ‘using up’ data/days until you actually land, and it locks onto the local network.
5Can I use two SIMs (eSIM and physical SIM) at the same time?
Yes. This is one of the greatest perks of having an eSIM over a physical travel SIM, as most modern phones support DSDS (dual SIM Dual Standby), meaning you can keep your physical home SIM for active calls and texts while your travel eSIM is handling all your data.
Knowing this helps answer the question below….
6Will I keep my home phone number for calls/texts while using a data eSIM abroad?
Yes – in the standard set-up, a travel data eSIM handles mobile data while your physical SIM will stay in your phone, meaning your home number will work for calls and texts.
7Does the eSIM support personal hotspot/tethering?
Yes, your eSIM will support hotspot, enabling you to connect multiple devices off just one eSIM.
Data and costs
8How much data do I actually need for my trip?
Light use
(maps, occasional messaging, and some browsing): 1-3GB per week
Moderate use
(social media, music, podcast streaming and video calls): 3-5GB per week
Heavy use
(video streaming, hotspotting and constant use of social media): 8GB+ for a week.
With the ability to top up on the go at Mozillion, the amount of data you purchased should never really be a stress, as even with too little, you can simply buy more.
9What happens when I run out of data?
As briefed above, if you run out of data, wherever you are in the world, simply add more, and it will go straight onto your existing eSIM – no need to download or purchase a new one.
10Is a travel eSIM cheaper than roaming with my regular carrier?
In the vast majority of cases, yes. Traditional roaming charges can swiftly increase by the minute, leaving payers with hefty bills of hundreds of pounds when abroad. However, with an eSIM, you know the price, and it doesn’t change once the plan is purchased – so no surprises to ruin your trip.
Coverage and flexibility
11Does the eSIM work in multiple countries?
Yes – this is one of the greatest reasons for people switching to eSIMs, as one purchase can cover you in hundreds of countries. For example, the global eSIM at Mozillion will keep you connected in up to 201 countries with one simple download – no queuing for new SIMs, no disconnection at the borders and no uncertainty.
12Can I install the eSIM before I leave?
Yes, and this is the recommended approach – install it when you’re at home, while on your Wi-Fi, before you travel. Here, it will sit dormant on your phone, not using up any validity.
Then, on arrival, as soon as your phone connects to a local network, the eSIM is activated and ready, meaning there is no fumbling around with QR codes when you arrive.
13What if I don’t have WIFI to download the QR code at my destination?
This is exactly why the recommended approach to eSIMS is to download it before you travel, meaning you don’t need to worry about this, as you will be connected as soon as you land. The workaround is to seek Wi-Fi wherever you can, whether that’s at the airport, cafes or borrowing a hotspot off a friend to quickly download the eSIM.
14Can I get a local phone number with a travel eSIM?
Most travel eSIMS are data only and don’t come with a local number. However, if you need a local number, e.g., for a local bank, you will need to look for a provider that explicitly offers this, or consider having a local physical SIM for your number and then your data eSIM to ensure you’re getting the best-priced data you can.
Trust, security, and practicalities
15Is an eSIM secure/ does it have the same protection as a physical SIM?
Yes. eSIMS use the same encryption and authentication standards as physical SIMs and even arguably improve on security due to there being no physical SIM that can be physically stolen or swapped. However, it is important to be careful about the QR code itself, where you should treat it like a password, as anyone with the QR code before you has activated it yourself could potentially install your eSIM profile
16Can I transfer or reuse an eSIM if I switch phones?
This will usually depend on the provider and the plan you choose. As the eSIM is embedded into your phone, the best option is to contact customer support, and they can issue a new QR code to download onto your new device.
17Are eSIMS refundable?
If the eSIM is unused and the QR code has not been activated, then a refund is possible.
The bottom line: the eSIM learning curve is mostly one-time. Once you understand that validity starts on activation, not purchase, the dual SIM lets you keep your home number and that installing before departure will save you from a lifetime of hassle at the airport then the whole thing becomes a lot less intimidating from your initial Google search.
