Qantas has been accused of unfairly devaluing the points of its 4.3 million frequent flyers with taxes and surcharges that can now add more than A$600 to what is supposedly a free ticket.

Additional fees on domestic frequent flyer tickets have now hit A$100 for a return flight - only slightly less than buying some cheap sale fares - and international travellers are slugged with charges ranging from A$200 to A$626.

Travellers wanting a frequent-flyer ticket from Sydney to Paris are among the hardest hit, shelling out 128,000 points and A$626 in taxes and surcharges on a return economy ticket. A return economy fully inclusive sale fare costs A$1970.

The airline hopes to sooth angst over the surcharges, imposed to cover the soaring cost of aviation fuel, by allowing domestic travellers to use points to pay for them.

Frequent flyers wanting to use this system face a flat levy of 6500 points on each domestic flight, but the move has been criticised as a backdoor way to raise the cost of redeeming tickets.

"What it does is reduce the value of the points because if you choose to pay the levy using points it increases the number of points it takes to get a free ticket," said frequentflyer.com.au website founder Clifford Reichlin.

Australian frequent flyers were slugged with higher charges than many countries where the fuel surcharge and taxes are often included in the ticket price for travellers using points, he said.

The Qantas strategy of levying a fuel surcharge outside the ticket price was also a major factor in devaluing its frequent flyer points, Mr Reichlin said.

Surcharge rises last month almost doubled the levy on non-stop flights to Europe to A$185 each way. They rose 47 per cent on US routes and 17 per cent on Asian flights. Mr Reichlin said fuel was an operating expense that should be included in the cost of the ticket.

"The only reason I can see for Qantas doing this is to slug frequent flyers."

A Qantas spokeswoman said taxes and charges had always been paid on redemption bookings and it was common practice.

"We think it's reasonable that the surcharges should apply to all customers as do other taxes and charges," she said.