The Sooner is always better when it comes to travel plans, particularly if you’re going overseas. While it’s probably best to go ahead and think about renewing a year out from the expiration date, at the very least you need to begin about three months before you plan to travel.

Remember that passport processing begins when a passport agency receives your application, not the day you apply. It may take two weeks from the day you mail your application until it’s “In Process.” Then, routine processing can take around 10 weeks, so plan for a 12-week interval until you receive your new passport.

While the U.S. allows travelers to use a passport until the exact date listed on the front page, that's not the case for many other countries. For example, if you want to check out the natural beauty of New Zealand, your passport needs to be valid for another three months past your trip. Want to spend a week on the beach in Thailand? Six months. (You can check the State Department's website for the specific requirements for different countries.) Even though some countries have more lenient requirements, it's better to play it safe.

Also, keep in mind that most countries require you to have a specific number of blank visa pages in order to enter the country. If you’re running out of blank pages, you will have to apply for a new passport — it's no longer possible to add pages to a passport book. Most passport books include 17 blank pages for visa stamps (there is an option for a larger book with 43 blank pages). The standard requirement is one or two blank pages but you can check for your destination on this handy chart to make sure.