eSIM vs roaming vs local SIM

Roaming is billed per day or per megabyte. Many carriers sell a daily pass that gives you your home allowance abroad for a flat fee, and a few include roaming in the plan for selected countries. Daily passes are convenient but add up: a two-week trip on a daily fee can cost more than a month of local data. Check whether the pass only applies to certain countries and whether it throttles after a data cap.

A local prepaid SIM is usually the cheapest option for a longer stay. You buy it at an airport counter, a carrier shop or a convenience store, show ID where required, and choose a data bundle. Tourist bundles with a set validity are common. The trade-off is time: finding a shop, waiting, and sometimes registering the SIM with your passport.

An eSIM is bought online from a travel eSIM provider or directly from a carrier. You pay for a data allowance and a validity window, install it by scanning a QR code or through an app, and it activates when you land. Prices vary widely by region and data size; short small plans are cheap, large long-validity plans cost more. Some providers include a phone number for calls, many are data-only.

Two hidden costs matter. First, hotspotting: some plans block it or count it separately. Second, top-ups: running out mid-trip and buying an add-on is usually more expensive per gigabyte than the original bundle.

Do the setup at home on reliable Wi-Fi, not in an arrivals hall. Install the eSIM or confirm the roaming pass, test that the line shows up in settings, and note which line is set for mobile data and which for calls and SMS.

Keep your home SIM active. Turn off data roaming on it so you do not trigger charges, but leave it on for calls and texts so one-time codes from banks and apps still arrive. Set the travel eSIM as the line for mobile data. If your phone supports it, turn on Wi-Fi calling on the home line so calls over Wi-Fi do not incur roaming rates.

Download offline maps, your boarding passes, the hotel address and a translation pack before you leave. Save the carrier's support number and your eSIM provider's app. If you use a physical local SIM, bring a SIM tool or a paperclip and a small pouch for your home SIM so you do not lose it.

Check the small print on validity: some eSIMs start counting from installation, others from first connection in the destination. Install too early and a short plan can expire before you land.

Registration rules: some countries require you to register a local SIM with your passport, and a few restrict how many SIMs a visitor can buy. Airport counters usually handle this for you.

Locked phones: if your phone is locked to a carrier, a local SIM or third-party eSIM will not work. Ask for an unlock before the trip.

eSIM support: not every phone has it, and some regional models lack it even when the global version has it. Check your exact model.

Two-line limits: some phones allow only one eSIM active at a time, or one physical SIM plus one eSIM. If you need three lines, you may have to swap.

Data-only eSIMs: many travel eSIMs give data but no phone number, so you cannot make ordinary calls or receive SMS on that line. Use your home line or a messaging app for calls.

Coverage: a cheap eSIM may ride on a smaller network with weaker rural coverage. If you plan to drive outside cities, check which network the plan uses.

Hotspot and fair-use caps: some 'unlimited' plans throttle after a set amount or block tethering.

Refunds: eSIM plans are often non-refundable once installed, so buy the right size first.

The questions below cover the choices travellers ask about most: which option to pick, the mistakes that cost money, and what to do before departure.