The budget carrier has blamed 'significant cost increases', but confirmed the fees went to easyJet and not to debit card processors or providers.
EasyJet corporate affairs manager Andrew McConnell told industry magazine Travel Weekly that the costs were needed to cover administration of the call centre, development and maintenance of the website.
'The booking fee covers a range of activities and EasyJet has experienced significant cost increases in a number of those areas.'
As well as the new £8 card fee per booking, Easyjet charges an additional £4.95 or 2.5 per cent of a transaction to credit card bookings. It pointed out that Ryanair charges a £12 fee per passenger on a return flight, while EasyJet allows multiple passengers for a single booking fee.
The easyJet charge was only £3.50 last September.
The carrier charges no fee on Visa Electron cards - in line with several other airlines. However, the UK Cards Association has previously reported these are held by fewer than one in ten UK consumers and most banks will not handle them.
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