An airline trade body hit back against the fines, saying EU law allowed them to set their own prices and fees.
Javier Gándara, chairman of Spain’s airline association, said that the four companies were preparing appeals against the fines, branding the penalties “disproportionate”.
Mr Gándara said that all airlines allowed passengers to carry a small item of hand baggage aboard, adding that EU law let them charge a supplement for suitcases over a certain size.
“In our country, some 50 million passengers a year travel without carrying a trolley suitcase, and they will be the most affected by this prohibition as they will have to start paying for a service they do not need,” he said.
Despite the EU ruling, British holidaymakers may not see immediate price drops on flights to the Costa del Sol.
Britain stopped short of banning similar excess baggage fees this month, despite Rishi Sunak commissioning a formal review into extra charges a year ago.
UK-registered airlines will still be allowed to charge extra for hand luggage or for booking a seat next to loved ones under the new Digital Markets, Competition and Consumers Act.
However, the act outlaws the hiding of add-on fees until the online check-out stage of buying a ticket, as many airlines currently do.
So-called drip pricing – advertising a fare, but then requiring passengers to pay extra for items or services offered as standard in the past – was described by Spanish officials as “an unfair commercial practice that hinders the comparability of offers and the decision-making of consumers, causing them significant economic damage”.
Many airlines charge passengers for cabin luggage despite a 2014 EU court ruling saying hand baggage of a “reasonable” size and weight is an essential element of travel and should not generate additional charges.