Obtain the renewal form for U.S. passports, form DS-82, online at Travel.state.gov. Fill out the form by providing all of the required information. Leaving anything blank intentionally or by accident means your application to renew your passport will be delayed or denied, and you might have to postpone or cancel your trip to Barbados, depending on when you plan on traveling.
Purchase a money order or write a check for $110 to the U.S. Department of State. This is the passport renewal fee as of 2011.
Mail your passport application, check and your current U.S. Passport, along with two new passport photos to the U.S. Department of State address listed on Form DS-82. Renewed passports are sent to you within six to eight weeks of receipt of your application. Include a check payable to the U.S. Department of State for $60 if you wish to expedite the processing of your renewal and receive your new passport in two to three weeks.
