Spain has fined five budget airlines a total of €179m (£149m) for "abusive practices" including charging for hand luggage.
Ryanair has been given the largest fine of €108m (£90m), followed by EasyJet's penalty of €29m (£24m).
Vueling, Norwegian and Volotea were issued with sanctions by Spain's Consumer Rights Ministry on Friday.
The ministry said it plans to ban practices such as charging extra for carry-on hand luggage and reserving seats for children.