eSIM vs international roaming: what a trip really costs
Your carrier will happily connect you abroad. The question is the bill. Here is how roaming is charged, what it comes to for common trips, and when it is still the sensible choice.
Roaming with your home carrier costs $5 to $16 for every day you use data, so a 10 day trip is $50 to $160 before taxes. A prepaid travel eSIM for the same destination is $10 to $40 for the whole trip, and your home number keeps working for calls and WhatsApp. Roaming only wins for a day or two, or when the country is already included in your plan.
How roaming is billed
Three models exist and most people are on the second without having chosen it.
- Pay per megabyte. The default on many plans outside Europe, at $2 to $10 per MB. An overnight photo backup can cost more than the flight. Carriers now cap it or switch you to a pass, but the cap is often $100 or more.
- Day passes. AT&T International Day Pass and Verizon TravelPass are $12 a day. Rogers, Bell and Telus charge CAD 15 to 16. EE, O2 and Vodafone UK charge £6 to £8 outside Europe. Telstra is AUD 10 and Airtel's one day pack is ₹649. You get your home plan's data, or a small allowance on the cheaper passes, and the fee applies to every calendar day your phone touches a foreign network.
- Included roaming. Canada and Mexico are included on most US plans. The EU is included for EU SIMs. Some UK and Australian plans include a list of countries. If yours does, roaming is free and you can stop reading.
Side by side
| On the trip | Travel eSIM | Roaming with your carrier |
|---|---|---|
| How you pay | Once, for the plan, before you go | Per day on your next bill |
| 7 days in the USA | $21 unlimited, or $10 for 5 GB | $84 on a $12 day pass |
| 7 days in Europe | $17 unlimited, or $6.50 for 5 GB | $84 for a US customer, £42 to £56 for a UK customer outside Europe |
| 14 days in Japan | $19.99 for 20 GB | $168 |
| 30 days in India | $59 unlimited | $360 |
| Your own number | Keeps working on the home SIM for calls and texts | Works as normal |
| Speed | 5G on the local network | 5G where your carrier has an agreement, often throttled after a daily cap |
| Setup | Scan a QR code once on Wi-Fi | Nothing, which is also the risk |
| Surprises | None. Prepaid, no bill | Days counted in the destination time zone, background data, taxes on top |
eSIM prices in US dollars from the ETravelSim product pages; the product pages show your currency. Roaming figures use a $12 day pass.
Three things the day pass does not tell you
A day is not 24 hours of use
On AT&T and Verizon the pass starts the first time your phone uses data abroad and runs 24 hours from then. Land at 11 pm, check a map, and a second pass starts the next evening while you are still at dinner. Other carriers use the calendar day in the local time zone. Either way a 7 night trip is usually 8 passes.
Background data counts
Email sync, iCloud or Google Photos backup, app updates and location services all use data without you opening anything. With roaming on, that is enough to trigger the day's charge even if you only used hotel Wi-Fi. This is the most common reason for the "I barely used my phone" bill.
Throttling after the daily cap
Several passes slow you to 2G speeds after 2 GB in a day. Maps still work, video does not. Most travel eSIM unlimited plans give 4 GB a day at full speed and then 1 Mbps, which is still usable for maps and messaging; some destinations, such as Japan and Thailand, have no daily cap.
When roaming is the right choice
- A day or two. $12 or $24 for a short business trip is reasonable, unless you already have the ETravelSim eSIM installed from a previous trip, in which case a $3.50 to $5 plan is less.
- The country is included in your plan. Check your carrier's roaming page for the destination before buying anything.
- Your phone is carrier locked. A locked phone cannot use an eSIM from another provider. Roaming is your only option until it is unlocked.
- You need your own number for incoming calls constantly and your phone does not support dual SIM. Most phones made since 2018 do, which removes this reason.
How to use an eSIM and still get your calls
This is the part people worry about. Your home SIM stays in the phone. You switch its data roaming off so it cannot generate charges, and leave it active for calls and texts. The eSIM becomes the data line. Incoming calls to your number still ring (your carrier may charge its normal rate for receiving calls abroad, often under a dollar a minute, zero on many plans). WhatsApp, iMessage and Telegram use the eSIM's data and keep your existing number. The dual SIM guide has the exact switches for iPhone and Android.
Country by country
We have written the comparison out in detail for the destinations people ask about most, with that country's eSIM prices and the typical roaming charge:
USA
From $3.50. Unlimited 7 days $21. US networks charge visitors the most, so the gap is widest here.
Europe
34 countries on one plan from $4.50. Unlimited 7 days $17.
United Kingdom
From $4. Unlimited 7 days $17, with UK number options.
Dubai / UAE
From $4.50. Unlimited 5 days $19.99. Roaming in the Gulf is among the dearest anywhere.
Thailand
From $8.49 for 5 GB. Unlimited 7 days $12.99.
India
From $4. Unlimited 7 days $19, 30 days $59.
Also: Turkey, Germany, Saudi Arabia, Egypt, Vietnam, Morocco, Russia.
Questions people ask
Will I still get calls and texts on my number?
Yes. Keep your home SIM in the phone with data roaming turned off. Calls and SMS arrive on it as usual; the eSIM only carries data. Incoming calls may be charged by your carrier at its roaming rate, which is often free or under a dollar a minute.
Can my carrier charge me a day pass while I am using the eSIM?
Only if data roaming is still on for the home SIM. Switch it off for that line and the carrier has nothing to bill. Leave roaming on for the ETravelSim line only.
Is roaming ever cheaper than an eSIM?
For one day, often yes: a $12 pass against a $3.50 to $5 one day plan is close, and the pass needs no setup. From two days on, the eSIM is cheaper, and for a week the difference is $60 or more.
Do I need to tell my carrier I am using an eSIM?
No. The eSIM is a separate prepaid line from a different provider. Your carrier is not involved and nothing changes on your contract.
What about calls to local numbers, like a restaurant or a taxi?
Use WhatsApp where the business has it, or choose a Data + calls plan. On selected destinations these include a number and call minutes.
Short version
For any trip longer than two days, roaming costs four to six times what a prepaid eSIM does, and you keep your number either way. Run your own numbers in the roaming cost calculator, then pick your destination.