Are you the sort of person who, instead of heading to the bank well in advance of your break abroad, leaves it to the last minute to exchange holiday money at the airport?
Well, that frantic let's-just-do-it-at-the-airport attitude is costing you £34 every time.
Brits flying out of Birmingham Airport are the hardest hit – getting £33.79 less on an average transaction of £262, compared with high street rates.
This is equivalent to 14 beers, 14 cokes and a bottle of sun cream if travelling to Sharm El Sheikh in Egypt, according to a study by the Post Office.
When it comes to the euro, tourists are being sold short by an average of £13.56.
Bob Atkinson, of travelsupermarket.com, warned that the airport is 'the worst place' to change sterling.
He told the Mirror: 'The rates are poor because they have a captive audience and they hit you with commission as well. The best rates are available online, using free delivery services.
'If you don't want to go online, then look at the high street, travel agents and banks, where no commission is charged.'
He said that families looking to get the best value from their holiday pound should think about a combination of cash ordered online and prepaid cards.
Sarah Munro, Post Office Head of Travel Money, said: 'With family budgets getting ever tighter, the message has to be to plan expenditure carefully.'
Feeling the pinch? See our top tips on slashing the cost of your next getaway:
Money worries cause 17m Brits to turn down holidays thus summer