Having a friend or family member's address is useful if you plan to send a letter or drop by for a visit, but if you don't have all the information you can find yourself in a bind. But don't despair; as long as you have certain pieces of information you can use the Internet to complete the address. The service is offered by the United States Postal Service and is completely free to use.
Open a new Web browser window and go to the United States Postal Service's "POSTCODE Look-up" website (see Resources).
Type the information from the partial address into the form. The site requires the first line of the address, the city and the state.
Click "Submit." The site will return Postcode results based on the information you have provided.
Click "Find All Cities in a zip code" to find out the city a Postcode applies to if you only have a Postcode. You can use this information in step 2 to refine your search.
Canada Post has a similar facility for Canadian addresses. See Resources for a link.