Frontier Airlines will let you fly for free if you have this last name

Is your last name Green or Greene? If so, you've lucked out because Frontier Airlines will give you a free flight if you fly on Aug. 13 as part of the company's Green Week promotion.

The airline's website explains how to book if you're eligible. First, reserve a flight for Aug. 13, 2019. You must book via the airline's website, flyfrontier.com. Frontier will then refund your trip.

The fine print? Flyers who can document that their legal last name is Green or Greene will get a refund for round-trip tickets as long as both segments are booked together and "the first segment departs between 12:00 a.m. and 11:59 p.m. on Aug. 13, 2019, and the return segment arrives by 11:59 p.m. on Aug. 20, 2019. Eligible participants will receive a full refund, up to $400."

The airline states you can expect to see the refund by Sept. 15. Spouses or family members who don't share your last name are out of luck.

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The giveaway is part of the airline's effort to promote fuel efficiency and sustainability. Frontier kicked off its Green Week on Tuesday with a flight from Denver to Greenville-Spartanburg International Airport, in South Carolina. Per a press release on Frontier's website, the flight was on "one of the most fuel-efficient aircraft in the world, the A320neo."

The airline explained the "greenest flight is focused on sustainability on every level" including "service items utilized include compostable cold cups, hot cups and napkins made from recycled materials and bamboo stir sticks."

It added, "To further lessen the environmental impact, Frontier is planting enough trees to offset the flight’s carbon footprint."

Frontier Airlines is known for its eye-catching giveaways. In May, the airline made headlines with a bring-a-friend-for-free promotion. The airline also announced a policy to let kids 14 and under fly for free earlier this year.

For both of those perks, you had to be a member of the airline's Discount Den loyalty program. The Green Week giveaway makes no mention of the program.

This article originally appeared on USA TODAY: Frontier Airlines will let you fly for free if your last name is Green