The cheapest flights online can be found two months ahead of departure, rather than a year ahead, according to a new study.
Travel search site Momondo found the cheapest prices can be found when booking on average 59 days in advance.
The 13 most popular routes from London were tested to Copenhagen, Paris, Berlin, Lisbon, Dublin, New York, Amsterdam, Barcelona, Madrid, Istanbul, Edinburgh, Glasgow and Los Angeles.
It found that travellers can save between 18%–51% on air fares, or an average of 38%.
This percentage saving is compared to the most expensive day to book, which 85% of the time is on the day of departure.
Finding the cheapest price around two months in advance was a uniform trend, despite the individuality of each route, distance and flight time.
All of the cheapest fares could be found by booking between 54 and 66 days in advance of the date of departure.
The greatest saving was on flights to Dublin from London which were 51% cheaper when booked 58 days in advance – giving an average price of £167 against £340 when booked on the day of travel.
Company spokeswoman Julie Pedersen said: “We are pleased to uncover some new trends around booking flights, proving it is always cheapest to book on average two months ahead of travel.
“The surprising fact for us also, was that at this point, flights are usually at their cheapest. So travellers need not book 6 or 12 months in advance, to find the best air fares.”