Monarch has extended its online check-in facility up to 18 days before travel.
The airline previously only allowed online check-in within seven days.
Online check-in can be used by all passengers with pre-allocated seats.
If seats have not been pre-allocated at the time of booking, passengers must pay £7.50 per one-way flight. Extra legroom seats, which offer an extra six inches of space, can be booked from £15 per flight.
Managing director Tim Jeans said: "We have seen overwhelming demand for online check-in, with over 20% of scheduled customers taking advantage of the service, in order to spend less time queuing at the airport.”
By Bev Fearis
