EasyJet is offering 500,000 seats at 20% off to celebrate its 20th birthday.
The sale launched on December 23 and will run until midnight on January 13. Discounts are valid for travel between February 4 and July 6, 2016.
Meanwhile, Flybe is also offering discounted flights, with 100,000 seats being offered for £30 or less up to December 31.
EasyJet has cut prices on flights to many of the most popular destinations from the UK including Geneva, Alicante and Marrakech. The sale also includes deals on popular UK destinations such as Bristol, Newcastle and Manchester.
Peter Duffy, commercial director said: “We’re delighted to be celebrating easyJet’s operation over the past two decades by launching our twentieth birthday sale today.
“Twenty years ago easyJet changed the way Europe travelled. We challenged the high price monopolies of the legacy airlines and enabled a new generation of people of all ages, incomes and interests to enjoy Europe.”
In addition to the flight discounts, the airline’s sister tour operator EasyJet holidays is offering up to 15% off more than 50,000 seven-night holidays for bookings made on the easyJet holidays website before midnight on January 13.
EasyJet celebrated its 20th birthday on November 10. It flies over 240 aircraft on more than 780 routes to over 130 airports across 33 countries.