Our general connectivity article concludes that a multi-country Asia trip wants a regional eSIM. Saily is the one we use. This article covers what it does, including the part that catches people out.
We earn a commission if you buy through the links on this page. We also travel on Saily, which is why it has its own article rather than being a programme we happened to be approved for. It is made by Nord Security, the company behind NordVPN. Our recommending both is a coincidence.
Who it suits
Several Asian countries, a couple of weeks, and a phone you rely on for maps and bookings: one eSIM you top up per country fits that trip, and Saily does it well.
What it does well
One eSIM, and you add destinations to it. Saily says: “Add new destinations to your existing Saily eSIM — no need to install new eSIMs every time. Just top up and connect!”
Bangkok, then Singapore, then Tokyo is three countries. With most providers that means three eSIM profiles to install and juggle in your phone’s settings. With Saily it is one profile you keep topping up. If your route has more than two countries, that outweighs a small price difference.
It activates itself on arrival. You install the app and the eSIM at home, and the plan “will activate automatically the moment you reach your destination”, in Saily’s words. The alternative is setting up a plan in an arrivals hall on a network you do not yet have.
Plans run from 1 GB to unlimited, priced per destination. Japan showed plans from US$4.99 when we checked on 1 September 2026. Other countries and plan sizes price differently, so we quote no other figure.
The catch: data only
You get internet, not a local phone number. Anything that verifies you by SMS, banks most often, still sends its code to your home number. Pick one of two fixes before you fly:
- Keep your home SIM active alongside the eSIM. The eSIM carries data and the home SIM stays reachable for texts. Most people should do this, so the answer to whether you can take your home SIM out is usually no.
- Add a number. Saily sells a US phone number as a monthly subscription, US$0.99/mo when we checked, and says “identity verification is required in the Saily app after purchase”. It is a US number, so it does not help with a local service that accepts only a local one.
When a local SIM wins
- A long stay in one country. A month or more in Thailand, and a local SIM bought in town gives more data for less money. The multi-country advantage is worth nothing if you are not crossing borders.
- A local number that local services accept. Some delivery apps, transport services and bank-linked payment systems want a local mobile number and will not take a foreign one. No travel eSIM fixes that.
- Mainland China. Treat it as its own problem and do not assume any eSIM solves it, for the reasons our VPN article sets out.
Check these at home
- Your phone is eSIM-capable and carrier-unlocked. A locked phone is the most common reason this plan fails, and you cannot fix it in a departure lounge.
- The app is installed and signed in. Downloading it on arrival means using the network you were trying not to depend on.
Saily plans for your destination (affiliate link)