Ryanair is to introduce charges for passengers who fly with a small suitcase.
The Dublin-based airline said it is overhauling its baggage rules to reduce delays.
Passengers who do not pay for priority boarding are currently permitted to take a small bag on board, while a second larger bag such as a wheelie suitcase up to 10kg can be put in the hold free of charge.
This policy was introduced in January as flights were being delayed by people struggling to find space for their luggage in overhead lockers.
But Ryanair said the change has resulted in up to 120 bags being tagged at gates for each flight, meaning departures are still being disrupted.
There will be no luggage carried in the hold free of charge from November, with passengers having to pay £8 to check in a 10kg bag. The existing charge of £25 for putting luggage weighing up to 20kg in the hold will remain.
The maximum size of small bags allowed on board - such as handbags or laptop bags - will be increased by 40% but they must still fit under the seat in front.
Passengers who pay for priority boarding - which costs £6 - will continue to be allowed to take a small bag and small suitcase as hand baggage.
Ryanair believes some customers may prefer the £8 option because they do not want to drag a wheelie case through airport security.
It claimed most passengers will be unaffected by the changes, as 30% already buy priority boarding and a further 30% only travel with a small carry-on bag.
The airline's chief marketing officer, Kenny Jacobs, said: "This new policy will speed up the boarding and cut flight delays.
"Sixty percent of customers will be unaffected by these changes and we expect that the other 40% will either choose to buy priority boarding or a 10kg check bag or will choose to travel with only one free small bag, as 30% already do so today."
The new policy will be implemented at boarding gates from November 1 and for all bookings made from September 1.
Non-priority customers who booked flights before September 1 for travel after November 1 and want to check in a bag can either add priority boarding or pay to have luggage in the hold. Alternatively, they can cancel their booking for a full refund.
Ryanair insisted it does not expect to make more money from the new rules, as it will lose revenue from passengers with checked bags switching from the £25 fee to the £8 option.