Australians took 7.1 million overseas trips in 2010 and spent an average of $5,000 per trip, independent finance comparison Web site Mozo said on Thursday.

While overseas, Australians were charged a total of $1.4 billion in the same year through foreign currency fees and other travel money charges that brought to $5,000 the average cost of a foreign trip.

"Our love of overseas travel is creating a lucrative business for the banks and travel money operators, who are slugging Aussie travellers with a confusing array of fees for spending money overseas," said Mozo Managing Director Rohan Gamble.

Mozo, which launched on Thursday Australia's first travel money comparison service to help travelers find the cheapest holiday money options, said travel money charges are often poorly communicated by the industry and not well understood by the average Australian.

A Mozo survey showed that one third of Australian holiday markers are unaware that they are being charged foreign currency commissions, another 20 per cent are unaware that they pay foreign cash withdrawal fees and 20 per cent did not know they were charged cash advance fees.

Banks often charge multiple layers of fees and commissions on a single overseas transaction. Most of these fees or charges related to overseas transactions are not explained in the bank statement, 30 per cent of holidaymakers complained.

With the new service, Aussies going abroad could compare foreign exchange rates and fees collected by major currency providers, check charges made when they use their debit or credit card overseas and seek the best pre-paid travel cards for their needs, Mr Gamble said.

However, of the $5,000 average spent by Aussies in their foreign trips in 2010, less went to Qantas. The air carrier's share of international travelers dipped to 18.7 per cent from 34.3 per cent of passenger traffic a decade ago.

To worsen Qantas's financial woes, three unions are restive and had struck several times in the past few months that led the management to bring their labor row to Fair Work Australia for arbitration.