Budget carrier Tigerair has been named the most complained about airline in Australia.

Budget carrier Tigerair has been named the most complained about airline in Australia.

The Airline Customer Advocate's (ACA) annual report shows the watchdog received 4.71 complaints about refund requests for every 100,000 customers Tigerair carried in 2014.

This compares with 1.11 refund requests for Jetstar, 0.75 for Virgin, 0.44 for Qantas and 0.28 for Regional Express over the same period.

Tigerair also received the most complaints concerning flight delays, airport customer service, terms and conditions as well as fees and charges.

The airline said its 2014 ACA results were adversely affected by airport infrastructure limitations and a number of flight network changes that impacted the airline's on-time performance.

"Both of these issues have been addressed and the airline's on time performance has improved considerably with consistently low cancellation rates," the airline said in a statement.

The ACA received 1132 complaints across all five airlines, an increase of more than 13 per cent on 2013.

Refund requests, delays and cancellations represent the main areas for customer dissatisfaction across airlines.