In the flexible saga of hand luggage on aircraft, British Airways has reduced the size allowed because it said that large passenger baggage was regularly causing flight delays.
From 18 August, one personal bag will be restricted to 40 x 30 x 15cm.
This bag can be placed under the seat which means that cabin crew will have to spend less time rearranging the overhead lockers.
The size of the main piece of hand luggage – which is often a bag with wheels – will remain the same at 56 x 45 x 25cm.
In an email to customers, BA said: “In recent months we have seen an increase in people travelling with hand baggage that exceeds their allowance.
“We always try to accommodate our customers but to make sure the aircraft is ready to depart on time we are making the following changes. You can continue to carry two pieces of hand baggage. One bag should be a handbag or laptop-sized bag which should now be no larger than 40x30x15cm.
“The size of your additional cabin bag remains unchanged and can weigh up to 23kgs. Customers who travel with hand baggage which is outside their allowance will be asked to check this into the hold.”
The change will hit those in economy and premium economy, but not those flying in first class.
The carrier says the move is to help ensure that flights depart on time.
"We are asking customers to help us achieve this by adhering to our hand baggage allowance which is clearly stated on our website," a spokesman said.