Under MaCUSA law you are required to carry a Wand Permit card at all times.

With this card you can prove to the authorities that you are allowed to carry a wand. The card itself is sized at 2 inches by 3 1/2, the size of a standard business card.
It comes blank, with approval stamp. It's an excellent addition to your American wizard cosplay or it's just fun to carry around in your purse or wallet everyday.