eSIM vs carrier roaming: how to work out the cost

Roaming bills by the day or by the gigabyte. An eSIM bills by the trip.

How each carrier charges

AT&T International Day Pass is $12 per day on land. Extra lines on the same day cost $6 each. The pass starts the first time you use data, text or call in an included destination and lasts 24 hours. You pay only for days you use it. AT&T's page says it applies to customers on an unlimited plan and that the data allowance comes from your home plan. It lists 210+ destinations (read November 2, 2026).

Verizon TravelPass is $12 per day in most countries. Each session gives 5 GB of high-speed data, then 3G speeds for the rest of the 24 hours. Verizon's FAQ says it will offer 2 GB more for $10 outside Mexico and Canada. In Mexico and Canada the rate is $6 a day, and free on Unlimited plans. Verizon also says use there may be limited if more than half your usage over 60 days is in those two countries.

Google Fi works differently. On the Flexible plan, international data costs $10 per GB, according to Google Fi's travel page. Unlimited Premium includes international data in 200+ destinations. On Unlimited Standard, Canada and Mexico are covered.

Run the numbers for your trip

Count the days you expect to use data abroad. Multiply that by the pass price: $12 a day for AT&T, $12 a day for Verizon in most countries. Then set the result against the price of an eSIM for the same country and trip length.

For the eSIM side, take one example. Airalo's Japan plan is 3 GB for 7 days at $8, data only (checked November 2, 2026). Your own destination will have a different plan and price, and your carrier's list has to include it. Plans for different countries don't share one break-even, so run the sum per trip.

The trip calculator lists eSIM plans for a destination. Put its price next to your days times the pass price.

Few days of use favour the pass: you pay only for those days and skip the install. Many days of use, or data you'd burn every day, favour a fixed eSIM, because a flat price stops growing while the pass keeps adding a daily fee. Google Fi's per-gigabyte rate favours a light user and punishes a heavy one.

Rules that change the answer

AT&T bills only on days you use the phone abroad, so a trip where the phone stays on Wi-Fi costs less than the headline rate. Verizon's 5 GB then 3G is a speed rule, and the line stays open. eSIM data is a pool: run out and it's gone, unless the plan offers top-ups. A roaming pass keeps your number. Many travel eSIMs are data only, so calls and texts stay on your home SIM if you keep it active.

My rule of thumb

On a short trip of 2 or 3 days on an unlimited plan, the day pass is fine. For a week or more, price a fixed eSIM first. At $12 a day, seven days of use is seven daily fees against one flat purchase.

Look at the eSIM side in the eSIM catalog. To see where unlimited eSIMs slow down, read unlimited or fixed data. Compare destinations in eSIM for Europe, or browse the best travel eSIMs.