Q. B”H – Shalom Dear Rabbi,
In Sweden, many people have started to use microchip implants to replace car keys, credit cards and ID Cards.
1. Based on Daat Torah, Is that permissible?
2.In case it becomes the law of the land, will that be permissible?
Thanks!

A. Horav Shlomo Miller’s Shlit’a opinion is that although the microchip cannot be used on Shabbos, one is allowed to carry it in a reshus horabbim, once it was placed inside the body. (See Piskei Teshuvos 301: 28, that all medical devices properly attached to the body, one is permitted to carry on Shabbos, even when not in actual use).
There is also no issue of chatzitza, when immersing in a mikva,
There is also no prohibition of cutting or piercing oneself when when the microchip is being installed, (chovel beatzmo, Bava Kamma 91b, Shulchan Aruch Y. D. 116)) since it is done for a specific need.
However, the Rov recommended abstaining if possible from implanting the device, as we are still unfamiliar with the long term effects it may have on the surrounding body cells.
There may be additional issues of security and losses by one’s identity being stolen, as the risks of the electronic code in the chip being copied are known, as it has often been done with credit cards etc.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a