Ryanair's new cabin bag policy comes into effect from today which will see only "priority boarding" customers allowed to bring two carry-on bags on the plane.
All other customers will only be allowed to bring one smaller carry-on bag on board, while their second (bigger) wheelie bag will be placed in the hold - free of charge - at the boarding gate.
The airline said that new boarding passes have been redesigned to clearly show whether a customer should queue in the priority or non-priority queue.
New signage and baggage sizers have also been installed at the boarding gates of airports where Ryanair fly from.
Ryanair has already introduced new reduced checked bag fees and increased check-in bag sizes to encourage more customers to check in bags and reduce the number of customers with two bags at the boarding gates.
Since September, the airline's check-in bag allowance has increased from 15kg to 20kg for all bags, while the standard check-in bag fee has been cut from €35 to €25 for a 20kg bag.
The airline also said today that it broke its weekly bookings record, taking over 3 million bookings in one week for the first time in its history.
Ryanair said that Wednesday January 10 was the busiest day for bookings last week and the most popular destinations for customers included winter holidays to Lanzarote and Tenerife and city breaks to Porto, Milan and Naples.
Kenny Jacobs, Ryanair's chief marketing officer, said the baggage changes would cost the airline €50m.
Mr Jacobs denied the changes were a way to extract more money from passengers and said the policy change had been well flagged and welcomed by most customers.
