All states set out legal procedures a person can use to change her given name, including first, last or middle. However, a person's signature is a different matter. A person is free to change a signature, and most people do alter the way they write their names between childhood and adulthood.. (+1) In my country the signature on national ID cards (not sure about passports anymore but I think it's the same) is taken from the application, digitalized and printed on the card itself. So it's not meant as an acknowledgment that you took possession of it.
You can change your signature whenever you want. There's no legal form you have to fill out or an official process to go through. You don't need to notify a government office. You just start using a new one. That said, consistency matters. Once you begin using a new signature — especially on important documents — it's best to stick.. If you change your name because of a change in your marital status (including marriage, divorce, entering or leaving a registered relationship or the death of a spouse), you can get a new passport or keep using your current passport. We recommend booking travel in the name that's in your passport. If you change your name for other reasons.