ESIM GLOSSARY

Data-only eSIM

Most travel eSIMs are data-only: they provide internet but no phone number, with calls handled by apps or your home SIM.

A data-only eSIM provides mobile internet but no phone number — you cannot make regular calls or send SMS through it. The overwhelming majority of travel eSIMs work this way, which keeps them cheap and instant to provision.

In practice this is rarely a limitation: WhatsApp, FaceTime, Telegram and every other app work over data, and in a dual-SIM setup your home number remains reachable for traditional calls and texts.

If you specifically need a local phone number abroad (for local bookings or verification), you need either a local carrier SIM/eSIM or one of the few travel eSIMs sold with voice add-ons.

Go deeper Keep your number: dual SIM setup →What is an eSIM? →