Go to the country's official government website for which you wish to renew the passport. For example, in the U.S., go to the U.S. Department of State website. For the United Kingdom, log on to the Home Office's website.
Fill out the appropriate passport application form. In the United States, fill out Form DS-82. This form is available online and in print.
Sign and date the application form.
Have two passport photos taken of yourself by an approved photography service. Passport photos must adhere to a number of government specifications, including that they are in color and sized to certain dimensions. In the U.K., a resident who has known you for at least two years must certify the passport photos.
Assemble an envelope of the application requirements, including the passport application form, your existing passport, two new photos and a form of payment for the passport fee.
Mail the completed envelope to the address listed on the application.
