But on USPS money orders, the blank is only labeled "From." Whether you write or sign your name is up to you.

How do I complete a Postal Order?

Write the sum of money into the small box marked with a “£” symbol, on the right-hand-side of the post order. This time you should use figures rather than words. Date the postal order on the line directly above the box marked wit a “£” symbol. Normally you would write the date on which you buy the postal order.

Who signs the back of a Postal Order?

(2) A receipt for the amount of the Postal Money Order shall be signed by the Payee or a person duly authorised to sign on his behalf.