There are several acceptable variations on the address, but all that is really necessary to write on the envelope is two lines: Santa Claus, North Pole. The post office will forward it to the proper address.
Santa doesn't have a real address. If you want to send the letter off you could always write on the front of the letter - Santa Claus 25 Reindeer Lane, NorthPole 345083. Your post office will then receive the letter and send it to Organization Projects to help the needy during Christmas time.
To mail a letter to Santa Claus, you only have to write "Santa Claus" and "North Pole" on the envelope. The post office does take such letters and will send them to the appropriate location.
