What is Data-only plan?

Not directly to a local number, because the plan carries no voice service. Most accommodation can be reached by email, a chat app or the messaging system of the platform you booked through. If yours only takes phone calls, ask for a chat channel at the time of booking or arrange someone who can call on your behalf.

Codes always go to your existing number, so keep the home SIM active to receive messages while switching off its data roaming to avoid unintended charges. The alternative is moving important accounts to a verification method that does not use SMS, which is best done at least a week before you travel since some services impose a waiting period.

Because issuing a number in any country involves number allocation, subscriber registration under local rules, and interconnection with local voice systems, all of which vary from place to place. Data alone is far simpler to deliver when one plan has to work across many countries, which is why most travel plans on the market are built this way.

Yes, and the quality depends mainly on how steady the connection is at that moment: good where the signal is strong, choppy where it is weak or heavily shared. The bigger constraint is that the other person must be on the same app, so agree on that with the people who matter before you travel.

Look for a plan that explicitly includes voice and messaging rather than an ordinary data plan. Availability differs by country, and some countries require identity verification before a number can be activated. Tell us the destination and dates and we can look at what options exist.

Leaving a line switched on to receive calls and messages is not the same thing as using data while roaming. The terms and charges belong to the operator that issued your number, so ask them plainly before you travel and keep the answer in writing. What you should certainly do is disable data roaming on the home line and let the eSIM carry all the data.