Twenty-year-old Jemma Redman from Kensington in Sydney's south-east was at the airport with friends on the morning of her flight to Bali when she was told she needed a new passport.

"We were checking in our bags and when I gave them my passport they said I couldn't go as it didn't have six months left," she said.

For travel to most other countries, Australian travellers must have a passport which is valid for more than half a year.

Ms Redman had "no idea" about the rule and didn't think her passport would be a problem as she had around five months until it expired.

She rushed to have new passport photos taken and applied at the Australian Passport Office.

"I had to pay a lot to get my passport express but we were only going on holidays for a week and a half so if I'd tried to get one the normal way it would've taken longer and I probably wouldn't have been able to go," she said.

Two days later Ms Redman was on a plane to Bali.

Ms Redman's friends and family were also surprised upon hearing her story and it has now become a "running joke" whenever travel is brought into conversation.

Flight Centre spokesman Haydn Long said the Christmas-New Year period is always the busiest travel time of the year and travellers should double-check their passports well before they board a plane.

"A passport is not a document that you look at every day, so you may not be aware that it's coming up to renewal time," he said.

"There are other requirements too that travellers need to be aware of. Some countries require you to have "clean" pages in your passport. If your passport doesn't have an unstamped page, you can be denied entry."

Mr Long recommended ensuring passports are in a good physical condition without any damage and that the holder's appearance hasn't dramatically changed since their last passport photo was taken.

According to the Department of Foreign Affairs and Trade, 215,980 priority passports were issued last year, with applications peaking at the end of the year.

Under this service, a passport can be processed year round at an extra cost in two business days, plus the handling and delivery time, saving travellers a potential three-week wait.

Between December 11, 2017 and January 6, 2018 the Australian Passport Office also offers a 48-hour priority service.

"The Passport RAPID service ensures faster delivery of passport applications to the Australian Passport Office and faster passports for clients during the Christmas and New Year period," a spokesperson from the Department of Foreign Affairs and Trade said.

"More than 650 people have applied for an Australian passport since December 11 under the Passport RAPID service."

Travellers with more questions about their passports should visit the DFAT website,