easyJet says it has launched its biggest ever flight sale, with up to 20 percent off 25 million seats.

Passengers booking any flights across the easyJet network between 6 and 10 January 2012 for flight departures between 1 February 2012 and 11 July 2012 will receive a discount of up to 20 percent. Travellers can avail these deals at easyJet.com.

In addition to the up to 20 percent discount off seats on easyJet flights, easyJet Holidays customers can enjoy a further £50 per booking discount on all bookings made on the easyJet Holidays website during the sale period for travel between 1 February to 11th July 2012, when the basket price of the chosen holiday is £700 per booking or more.

easyJet’s hotel partner Laterooms is also offering up to 50 percent off accommodation for stays until 6 January 2013 which are booked during the sale period and Europcar, easyJet’s car hire partner is offering 20 percent discount on all rental bookings made between 6 January 2012 and 10 January 2012 for car rental from easyJet destination airports starting between 1 February 2012 and 11 and July 2012.

The airline clarified that some date restrictions may apply in some destinations.

The sale will be publicised through television and radio advertisements along with ads in national newspapers and banner ads online.

In its results for the year ended 30 September 2011 released in November last year, the airline shared that passenger numbers rose 11.8 percent to 54.5 million and load factor improved by 0.3 percentage points to 87.3 percent. Passengers originating outside of the UK accounted for 56 percent, an increase of three percentage points compared to the prior year. Passengers travelling with easyJet on business increased by almost one million to 9.5 million.

Total revenue per seat up 4.1 percent (3.4 percent on a constant currency basis) to £55.27 as capacity investments made in FY’10 and the first half of FY’11 matured, combined with a strong performance from ancillary revenue, up 12.9 percent to £11.52 per seat following decisive management action in the second quarter.

The airline also shared that with around 45 percent of winter seats sold, in line with the prior year, first half passenger revenue per seat is expected to grow by mid-single digits with planned improvement in yields, bag charges and other ancillary revenues.