An eSIM is—in principle—a SIM card integrated into a device that can be reprogrammed repeatedly via an eSIM profile with new plans and providers. This usually works via a so-called QR code —a rectangular block made up entirely of dots that can be scanned with a smartphone camera. This QR code contains a link to the provider’s server, where the eSIM profile is stored, as well as information about the plan to be used. The smartphone (or eSIM-enabled router) now needs an internet connection to access this eSIM profile, read it, and write it to its internal SIM card.
The biggest advantage of this solution is that you can purchase a plan online and start using it right away, without having to go to a store or wait for the SIM card to arrive. In addition, there are countless eSIM providers, some of which offer very attractive plans. For example, in Austria, you can get one month of unlimited internet on a prepaid basis for less than 20 €. In Spain, 20 euros gets you 350 GB, and the situation is similar in Denmark and many other countries. All of these plans are also available as eSIMs.
Since most mobile routers—as well as many older (and some newer) smartphones)—do not support eSIM profiles, there is a solution that allows you to use an eSIM even in a standard router. The magic word is“physical eSIM card.”This rewritable SIM card is programmed with the eSIM profile in an Android smartphone and then works like a regular SIM card in any smartphone or router. It can be reprogrammed again and again.