If you're planning to travel internationally in the next year, it's time to check the expiration date on your passport. While processing times for passport renewal can vary (it typically takes four to eight weeks, depending on seasonality), travel experts and the U.S. Department of State recommend starting the process as early as possible. However, if you're in a rush, you can choose expedited service – and receive your passport in two to three weeks – or you can visit a regional passport agency, but both will cost extra. Read on for a step-by-step guide from U.S. News on renewing your passport.Passport Renewal by MailIf your passport was issued less than 15 years ago (and you still have it), you can renew your passport by mail. You'll need to submit the existing passport, a new photo that meets passport requirements, a completed Form DS-82 and a personal check or money order for the fee. The fee for a standard passport book application is $110, and payment must be made out to the U.S. Department of State and include the full name and date of birth of the applicant. If your name has changed since your last passport was issued, you'll need to also provide documentation, such as a marriage certificate, divorce decree or court order, to prove the name change.You can mail all your materials in a large envelope, including your old passport and any name change documents, through the U.S. Postal Service to one of the National Passport Processing Center's designated post office boxes. The address varies depending on what state you live in and whether you choose expedited or routine service. Expedited service ensures you'll receive your new passport faster, but it will cost an additional $60. To expedite your passport by mail, clearly write "EXPEDITE" on the outside of the envelope. You can also choose to expedite the process by renewing in person, but you'll pay the same additional fee. The Department of State also recommends applicants use a trackable delivery method.[Read: How to Get Your Child a Passport.]Passport Renewal in PersonIf your passport has been damaged, lost or stolen, or if it's more than 15 years old, you'll have to renew in person. You'll need to fill out Form DS-11 and provide proof of U.S. citizenship along with a photo ID. Proof of citizenship can be an original or certified copy of a U.S. birth certificate, a certificate of naturalization or citizenship, or a consular report of birth abroad. Your identification document can be a driver's license, a government employee or military ID, a valid foreign passport or a certificate of naturalization or citizenship.Keep in mind, applicants can use an expired passport as either evidence of citizenship or photo ID, not both. No matter what evidence you decide to provide, you'll need to supply the documents in person, as well as submit photocopies of both your proof of citizenship and your photo ID. You'll also need to provide a check or money order made out to the Department of State for the $110 fee, along with a photo that meets passport requirements. Credit cards are not accepted when renewing in person. When renewing your passport in person, you'll also need to pay a $35 execution fee. An additional $60 fee applies if you choose expedited service.Once you've gathered all your materials, you can make an appointment to visit a passport acceptance facility near you. Facilities range from post office locations to clerks of courts to other government offices. Some passport acceptance facilities include on-site photo facilities as well. Keep in mind that you shouldn't sign your passport application until you're instructed to by an acceptance agent.Passport Renewal for MinorsPassports for children younger than 16 are only valid for five years, so parents will need to keep that in mind when obtaining and renewing passports for youngsters. Much of the same documentation used when first applying for a child's passport will be needed for a renewed version. This means you'll have to fill out the DS-11 form, provide proof of citizenship and present photo ID (as well as photocopies of both), submit a photo and pay the appropriate fees. Additional documentation is required to prove the parental relationship (like a birth certificate or adoption decree), and proof of parental consent is mandatory from both parents. The cost for renewing a child's passport is $80, plus the $35 execution fee for applying in person. For more information on renewing a child's passport, visit the Department of State website.[Read: Do You Need a Vaccination for Your Next Trip?]Passport Photo RequirementsWhether you're applying by mail or in person, you'll need to provide a photo that was taken in the last six months to go along with your passport application. The 2x2 color photo should have a white or off-white background with your head facing forward and a neutral expression or natural smile (don't show your teeth). Keep in mind that glasses, hats and head coverings aren't allowed in passport photos, except for medical and religious purposes. If that applies to you, you'll need to provide a written statement from your doctor or religious official that verifies your traditional attire. You can obtain a passport photo from select post offices, passport acceptance facilities and some major drugstores. You can learn more about specific passport photo requirements from the Department of State website.