The Office of Fair Trading (OFT) has threatened travel firms with enforcement action over surcharges placed on customers who pay by debit or credit card.
The consumer watchdog handpicked the airline sector for using the practice as UK customers spent around £300 million on surcharges in 2009 - an unwelcome added holiday expense on top of flights, spending money and travel insurance.
While it refused to name the worst offenders the OFT did reveal that easyJet charged £8 for every debit or credit card transaction, Ryanair added £6 and Trainline charged £3.50 for a credit card payment.
The watchdog will urge the Government to ban surcharges on debit card transactions, but because of how costly credit card payments are to process, they will recommend that the surcharges remain.
However, the OFT is pushing for additional credit card charges to be included in the headline price and not merely 'tacked on' at a later stage to stimulate further competition between firms and avoid confusion.
Investigators began looking into payment surcharges after a super-complaint lodged by consumer body Which? in March after it found surcharges were "increasingly widespread".