eSIM, Local SIM, or Roaming: Picking One Before You Land

You have three ways to stay online in Asia: roaming, an eSIM or a local SIM. Most people compare price per gigabyte and pick the wrong one. Compare price per hour of your own time.

Decide at home. Leave it until you land and you arrive tired, in a hall designed to sell you the most expensive version of whatever you did not arrange, and you take it. Fifteen minutes before you fly avoids that.

Roaming: expensive, and sometimes correct

Roaming on your home plan usually costs the most per gigabyte and the least effort. Your number works, messages arrive and two-factor codes land as normal from the moment you walk off the plane.

For a short trip to one country that is often the right trade. Most carriers sell a daily rate, so a week is a known cost and your first afternoon is your own. Duration and borders change the sums: multiply that rate by three weeks, or cross four countries and find out which ones your plan actually covers.

eSIM: the default for most trips

An eSIM is a data plan you install before you leave, so there is no shop, no queue and no card to swap when you are most tired. Most regional plans cover a group of countries on one profile, which suits a multi-country Asia trip. We travel on Saily, which works that way: you add destinations to one profile instead of buying a new eSIM at every border.

Two things catch people out.

• Most travel eSIMs are data-only. You get internet but no local number, so anything sent by SMS still goes to your home number. Keep your home SIM active alongside it.
• Your phone must be eSIM-capable and carrier-unlocked. Establish that at home, not at a boarding gate. A locked phone is the single most common reason this plan fails.

The providers publish compatibility lists, and checking takes a minute. Ubigi’s list covers iPads and Windows laptops as well as phones, which helps if you work from a device other than your phone. Carrier locking is set by your own operator, so no list covers it. Ask them before you pay for anything.

Install the eSIM before you fly and leave it switched off until you land. Activation usually starts on first connection, and you do not want day one of a seven-day plan to pass in your own kitchen.

Local SIM: cheapest data, most friction

A SIM bought at your destination gives the most data for the money and a local number that local services accept: useful for domestic transport bookings, delivery apps and anything that verifies by SMS.

The cost is effort:

• Registration rules differ by country, and several require your passport at the counter.
• Airport kiosk prices are consistently worse than the same operator’s shop in town.
• You are now running two numbers.

How we decide

Count the countries and the weeks.

• One country, under two weeks: roaming if your carrier’s daily rate is sane, an eSIM if it is not.
• Several countries, any length of trip: almost always a regional eSIM. Our Saily and Nomad comparison shows which of the two suits which trip, since they price in completely different ways.
• One country for a month or more, or you need a local number that local services accept: a local SIM, bought in town rather than at the airport.

Whichever you choose, check your own model against the list before you buy anything. An incompatible handset makes the rest of this decision irrelevant, and you cannot fix it from an arrivals hall.