Millennials are changing the travel industry.

The frugal and tech-savvy generation that so many people bemoan has prompted big hotel companies to launch affordable, hostel-like lodgings and install voice-activated assistance in rooms, according to Smarter Travel.

It's backed a booming peer-to-peer industry. It's demanded that low-cost accommodations and budget airlines no longer be a seedy alternative.

And now, one online travel agency, based in the United States, is catering to people who don't have credit cards - most of whom happen to be millennials.

Advertisement allows customers to make monthly payments on plane tickets instead of paying upfront, which means travellers can now book and take an expensive flight, but pay for it later.

This "Travel Now, Pay Later" option will make pricey, last-minute flights a lot easier to book, and could also open doors for people who simply can't afford flights.

CheapAir's payment plans are backed by Affirm, a loan serviced that will collect monthly payments at 10 to 30 per cent interest, depending on a "soft" credit eligibility check.

Purchasers spending more than $US100 on fares will be able to choose between three, six, or 12-month financing plans.

CheapAir says it's offering payment plans in light of findings that suggest 67 per cent of American 18 to 29-year-olds don't have a credit card.

The study cites student loan debt as one reason younger people might not want to use credit, as well as financial problems that occurred during the Global Financial Crisis of 2007.

"Credit card issuers, in many respects, have not kept up with the times and there are an increasing number of alternatives now available," Jeff Klee, CEO of said.

"We want to give everyone the freedom to travel, regardless of whether or not they choose to use credit cards."

Millennials (and others) without credit cards, rejoice.