[What should I do when I start using eSIM for the first time? Summary of precautions for each carrier] --Keitai Watch

What is eSIM?

eSIM downloads and installs a "profile" delivered via the carrier's website or e-mail on a device such as a smartphone with a built-in eSIM chip.

Roughly speaking, it would be easy to say that the work of "replacement" of a plastic SIM card (physical SIM) is done via the Internet.

For details on eSIM, refer to the basic knowledge of mobile phone terms.

Unlike conventional physical SIM, eSIM eliminates the need to deliver SIM cards using a realistic distribution network.

Therefore, if you complete the application procedure for a new contract online, you will be able to use the service within an hour at the earliest, and you will be able to use the communication service in a shorter time than before without visiting the store.

Due to the pandemic of the new coronavirus infection, there are more restrictions on overseas travel, so it is more difficult to go back and forth more easily than before, but if it is eSIM that does not depend on the physical distribution network, it is at the destination. It is not difficult to get the communication service to use before departure.

Also, with physical SIM, if the SIM card size does not match, it is necessary to replace the SIM card, but the user side does not have to be aware of the physical "size" eSIM is a SIM card supported by the terminal side. You don't have to worry about the size of.

On the other hand, as of September 2021, except for the case of selecting eSIM when making a new contract or changing the model with a terminal and line as a set, in principle, download not only compatible models such as smartphones that support eSIM, but also eSIM profiles. A communication method for confirming the QR code for and a display for displaying the QR code are required in addition to the device on which eSIM is installed.

In other words, in addition to the smartphone that inserts eSIM, a device (smartphone, tablet, computer) that displays eSIM is required.

The reason for this is that, except for the services of some operators, when installing eSIM, the QR code is displayed on the display of a personal computer or tablet, and the QR code is read by a smartphone or the like.

If you can download the "eSIM profile" directly to your smartphone, you can start using eSIM more easily, but at least at the time of writing this article, "When you start using eSIM, you should use a device other than the one that uses eSIM. Remember that a communication line is required for installation. "