Going international soon? Better act now.

Last week, the State Department warned travelers to renew their passports as soon as possible because nearly 49 million will expire in the next three years, causing a major logjam of renewal requests that could take six weeks or more to fulfill.

Why is this happening? In part, it’s because nine years ago a law began requiring U.S. citizens to have passports when traveling to Canada, Mexico, Bermuda and the Caribbean. Passports are only good for 10 years (five years for kids), so everyone who got a passport when the law went into effect is coming up on expiration. That, coupled with regular renewals, could cause significant delays, the State Department said.

In Austin and need to renew your passport? Here are five things you need to know.

Officials are expecting a flood of renewals of 10-year passports issued in 2006 and 2007, when they were for the first time required for Americans returning by air from Mexico, Canada, the Caribbean and Bermuda. Photo by James Nieves / The New York Times

You can renew by mail if your passport: is undamaged and can be submitted with your application; was issued when you were 16 or older; was issued within the last 15 years; and was issued in your current name (or you can legally document your name change). A passport does not have to have expired to be renewed. Anyone 15 or under must apply in person using form DS-11. If you need to appear in person, go to the Travis County District Clerk’s Passport Acceptance Facility (5501 Airport Blvd., north entrance, Room 220, Austin, 78751). It’s open from 8 a.m. to 4 p.m. daily but wait times can be significant. If you arrive late in the afternoon, you may not be seen. Once your application is processed, your new passport will be mailed to you within about six weeks. (You will also receive your old passport separately in the mail.) Some post offices and other locations in Austin also accept in-person passport applications. Call ahead, though, as some only process passports on certain days and during certain hours. To renew your passport you will need to pay a $25 passport processing fee and a $110 passport renewal (for applicants 16 and older — applicants under 16 are $80). If you need your passport back within three weeks, you can pay an additional $60 expedited service fee (see website for updated processing times). Need it even faster? Go to Houston or Dallas. Houston and Dallas each have a U.S. Department of State Passport Agency. If you go, you’ll need to make an appointment ahead of time and have proof of immediate (within two weeks) international travel or a life or death emergency. You will be required to pay the additional $60 expedited service fee on top of your renewal and processing fees for appearing in person at the agency. If you arrive in the morning with all of the correct documentation, the agency will process everything and leave your new passport for you at will call, frequently on the same day.