Bare in mind switching license plates does cost money, but yeah u can move them from car to car.
Furthermore when buying a new car the "spare" license plate in your storage will get used on the new car, meaning if u ever buy a new car the extra license plate you had needs to be bought again for a few thousand (i think random plate is between 10-30k?) to be able to switch out the license plate. (not needed in the first instance of buying a custom licensplate as u remove the original on the car just when buying extra cars)