Coming home from a trip to a phone bill bigger than your hotel stay is a nasty surprise, and it still happens to plenty of travellers. The good news: avoiding it is straightforward once you understand how roaming actually works. You can cut the cost to almost nothing, keep your usual number active for the calls and texts that matter, and still have fast data the moment you land. Here is exactly how to organise it.
Why roaming bills get so big
When you travel, your phone tries to connect to a local network in your destination. If your home plan does not include that country, your provider charges you to "roam" on that partner network, and those rates can be eye-watering compared with what you pay at home. Data is usually the biggest culprit, because apps keep working in the background: syncing email, updating maps, backing up photos, streaming that video you forgot to close.
The other trap is assuming your allowance travels with you. Some plans include roaming in a handful of nearby countries but charge full rates everywhere else. One afternoon of maps and messaging on the wrong network can quietly rack up a serious bill before you have even noticed.
Step one: turn off data roaming on your home SIM
The single most effective move is to stop your home SIM from using data abroad. This prevents accidental charges while keeping the SIM itself active for calls and texts if you want them. Here is where to look:
- iPhone: Settings, Mobile Data (or Cellular), Mobile Data Options, then switch Data Roaming off.
- Android: Settings, Network and internet, SIMs, select your home SIM, then turn Roaming off. Menu names vary slightly by manufacturer.
With data roaming disabled, your phone will not pull data over the foreign network. You can still receive calls and texts on your number, though be aware that answering calls while abroad can carry a charge from your provider, so check your plan's terms before you rely on it.
Step two: get your data from a travel eSIM
This is where the real saving happens. Instead of paying your home provider's roaming rates, you install a travel eSIM that gives you local data at a fraction of the cost, often from a few pounds for a trip. An eSIM is a digital SIM built into most phones from 2019 onwards, so there is nothing physical to swap and nothing to lose.
The setup is quick. You buy a plan for your destination, the QR code arrives by email the second you pay, you scan it, and the eSIM installs alongside your existing SIM. Your plan only starts counting when you first connect at your destination, so you can sort everything out from your sofa before you fly. If you are not sure whether your handset supports it, our compatibility checker takes a few seconds, and the how it works page walks through the whole process.
Because these are data-only plans, they pair perfectly with the roaming switch you just turned off. Your home SIM stays quiet on data, and all your browsing, maps, and streaming run through the cheaper eSIM instead.
Step three: keep your number working with Wi-Fi calling and apps
Here is the part that worries people most: "If I am using a data eSIM, can people still reach me on my normal number?" Yes. Your physical SIM or number stays active, so WhatsApp, iMessage, and your usual contacts keep working exactly as they do at home. A data eSIM does not replace your number, it simply carries your internet.
To make and receive regular calls and texts on your home number without roaming charges, use these options:
- Wi-Fi calling: If your provider supports it, your phone routes calls and texts over the internet using your normal number. Turn it on before you travel (iPhone: Settings, Mobile Data, Wi-Fi Calling; Android: Settings, Network and internet, then look for Wi-Fi calling). It works over your eSIM data too, not just hotel Wi-Fi.
- WhatsApp, iMessage, and FaceTime: These run entirely on data, so calls and messages to friends and family cost nothing beyond the data they use, which your eSIM covers.
- Set your eSIM as the data line: In your dual-SIM settings, choose the eSIM for mobile data and leave your home SIM for calls and texts. That keeps costs predictable.
Share your connection with hotspot
Travelling with a partner, family, or a work laptop? Most travel eSIM plans are data-only with hotspot sharing, so you can tether a second phone, a tablet, or a laptop to your connection. One plan can cover the whole group's browsing, which saves everyone buying separate data and keeps the bill in one place.
A simple pre-departure checklist
Run through this the day before you leave and you will not have to think about it again:
- Turn off data roaming on your home SIM.
- Buy and install your destination eSIM, then set it as your data line.
- Switch on Wi-Fi calling so your number still works for calls and texts.
- Check that WhatsApp and iMessage are signed in and working.
- Confirm your handset supports eSIM if you have not already.
There is no account to create and no contract to sign, so guest checkout gets you sorted in minutes. And because plans come with a 30-day money-back guarantee, there is no risk in trying it before your next trip.
Travel connected, not overcharged
Avoiding roaming charges is not about switching your phone to airplane mode and hoping for the best. It is about splitting the job: your home number handles calls and texts over Wi-Fi calling, and a cheap data eSIM handles everything else. Browse travel eSIMs for 190+ destinations and set yours up before you fly, so the only surprise waiting when you get home is how much you saved.