Usually not, because a typical travel plan sells data only and carries no telephone number. Calls through apps such as LINE or WhatsApp work normally, since those run on data. If you genuinely need a number, check the plan details before buying — only some plans include one, and the conditions differ by provider and by country.

The most direct approach is to keep your home line in the phone with its mobile data and data roaming switched off, so texts arrive while nothing runs in the background. The alternative is to move that service to an authenticator app, which should be done before you leave, because the switch itself usually requires one more confirmation text.

Yes. Receiving a call does not use data, so as long as the home line is switched on and can attach to a local network, incoming calls still arrive. What it costs to receive them abroad follows your home operator's rates, so ask them beforehand and decide whether to leave the line on all the time or only when you need it.

It depends far more on the signal and the speed available at that moment than on the app. With a good connection the quality is usually comfortable; on a weak signal, or after a plan's speed has been reduced, audio can break up. Choosing a voice call over video and moving to a spot with better signal before an important call both help.

If your travel profile has no number, either call from the home line knowing your operator's rates, or reach the property online — through the chat in the booking app, by email, or via the hotel's own contact page. Those are usually just as quick and cost nothing to use.

Message us on LINE at https://lin.ee/skDPoNx, the account @esimonline, or write to esimonline.asia@gmail.com. We have no telephone line for support. When you write, attach screenshots of the list of lines and of the roaming settings, along with your order number, and we can look into it far more quickly.