1 year of post FUE transplant can I shave my head with a razor?

After one year there is no reason why you cannot cut your hair or shave your head with a razor.   It may defeat the reason why you had the surgery in the first place.

Hello, Thank you for your question. It is completely ok shaving with razor 90 days after your operation.

You can certainly shave your head one year after a procedure; however, you may have visible scars from the FUE extraction sites. The length of hair you must maintain depends upon the characteristics of your hair including hair color, caliber, curl, and skin color, and the size/number of the FUE scars in the donor area. 

Yes, generally it's fine to use a razor on the head once a month from the surgery has passed. At a year you should definitely be safe.

At one year you can cut your hair anyway you like, even with a razor if you like a razor cut. These hairs should be completely normal by this time

You will have no issue at all shaving your head with a razor after a year. After 1 month you are safe to do so.