During a recent visit to the Minneapolis Passport Agency, I saw a few families and individuals occupying the lobby. Most were there because they needed passports — fast. Maybe they checked their passport expiration date only when the packing began for an international flight, or they needed to suddenly visit family in another country, or they were denied boarding at the airport because their passport will expire in five months (more on that later).

Me? I just wanted a behind-the-scenes look at the agency, which has issued more than 1 million passports since it opened in 2009. It serves citizens of Minnesota and the Dakotas who need expedited passports, and it can turn them around in hours. Here's what I learned:

While the Passport Agency is intended to help citizens in need of a quick turnaround, it opens its doors to anyone seeking expedited or routine service on the annual Passport Day, taking place this year on May 18 from 9 a.m.-2 p.m. at the Old Federal Building (212 3rd Av. S., Mpls.). To book an appointment, call 1-877-487-2778. The usual expedited service takes two to three weeks for an additional $60 fee above the standard passport cost; routine service could take up to six weeks. Applicants are encouraged to bring their own passport photos to the event, but the U.S. Postal Service will be in the building taking photos.

Which brings me to another lesson I learned during my tour: It is not unusual for passport applications to be delayed because of a missing piece — and often that missing piece is a passport photo that doesn't fit the highly specific requirements laid out by the U.S. Department of State. The agency trains its federal partners in how to take a usable passport photo, but the training is not mandatory at nongovernmental places that offer the service, such as pharmacies.

One of the most common reasons people end up needing expedited service: They learn at the airport that the country they are visiting requires a passport's expiration date to be at least six months from the dates of travel. That includes most of Europe.

Send your questions or tips to Travel Editor Kerri Westenberg at travel@startribune.com, and follow her on Twitter: @kerriwestenberg.