eSIM vs roaming: what actually costs less
Roaming passes are easy, but easy isn't always cheap. How to compare roaming and a travel eSIM for your own trip, in five minutes.
3 min read
Your home carrier would like you to roam. Travel eSIM sellers, us included, would like you to buy an eSIM. Instead of throwing numbers at you, here's a simple way to work out which is cheaper for your own trip.
How roaming is usually priced
Carriers package roaming in different ways, but most fall into one of these:
- Daily pass. A fixed fee for every day you use data abroad. Some passes slow you down after a daily allowance.
- Pay as you go. Charged per megabyte. This is the classic source of bill shock and almost always the most expensive way to use data abroad.
- Included roaming. Some plans include roaming in certain countries. For example, SIMs from EU countries can generally roam within the EU at domestic rates. If that applies to you, check the fair use limits.
How a travel eSIM is priced
A travel eSIM is a prepaid data plan: one price for a fixed amount of data and a fixed validity. With OneSim that's 1 to 50 GB, valid for 30 days from when the eSIM first connects at your destination. There's no daily fee, nothing renews and you can't run up a bill. If you need more, you top up the same eSIM.
The trade-off: our eSIMs are data only, with no phone number. You keep your home SIM for calls and texts, or use WhatsApp and FaceTime over data.
Do the math for your trip
- Look up your carrier's roaming price for your destination, in its app or on its website.
- If it's a daily pass, multiply the price by the number of days you'll use data. Count arrival and departure days too.
- Estimate how much data you'll use. Our guide to data for a one-week trip helps.
- Find the price of an eSIM plan of that size for your destination.
- Add anything else roaming would cost you, like calls or texts you'd make on your home number.
A useful rule of thumb: a daily roaming fee grows with every day of your trip, while an eSIM price stays the same. The longer the trip, and the more phones in your family, the bigger the difference tends to be.
When roaming can make sense
- Very short trips. For a single day across the border, a one-day pass may be simplest.
- Roaming is already included in your plan for that country.
- You need your number for lots of calls. If you'll be making regular phone calls on your own number, roaming keeps that simple, though calls abroad are often charged separately.
When an eSIM usually wins
- Trips of several days or more, where a daily fee would add up.
- Families or groups, where each phone would pay its own roaming fee.
- Frequent travellers who want a predictable cost per trip.
- Anyone who wants to know the full price before leaving home.
The best of both
You don't have to choose just one. Most eSIM phones can keep two lines active: leave your home SIM on so you still receive texts like bank verification codes, but switch data roaming off for it, and use the travel eSIM for all your data. Check with your carrier whether receiving calls or texts abroad costs anything on your plan.
For a side-by-side overview, see our page on eSIM vs roaming.
