A return address is the information about the sender that help the letter find its way back to that person if it is undeliverable. The return address is written at the top left corner of the envelope or package.
The return address should list the sender's name, street address, city, state and ZIP code. If, for some reason, the letter or package cannot be delivered, the postal service will return the parcel to this return address.
When writing the state in the return address, as well as in the recipient's address, postal abbreviations should be used. These abbreviations are written in capital letters without punctuation. For example, the postal abbreviation for Texas is TX and the abbreviation for New York is NY.