The company said the move "will ensure eligible tickets are refunded to the passenger's bank within seven days of request".

However the company said that current high volumes of requests during this period could mean the refund may take longer and in a recent communication with a passenger said it could take up to four weeks to receive the funds.

Rex says it's COVID Refund Guarantee is unique because it provides for a full refund for passengers whose flight plans on Rex are directly impacted by COVID-related travel restrictions due to border closures, lockdowns and quarantine requirements.

Rex deputy chairman, John Sharp said that Rex had cancelled hundreds of flights due to the recent border closures and lockdowns.

"Consequently, tens of thousands of Rex passengers are facing cancellation of their flights. Without our ground-breaking automated portal, it would take us weeks if not months to manually process this volume of requests," Mr Sharp said.

"Rex is a full-service airline that provides its passengers with the highest level of service, and processing refunds in a speedy manner is part of its dedication to its passengers," he added.

Mr Sharp took aim at Qantas suggesting that Qantas passengers suffer "indignity and anguish" when trying to get a refund.

"Rex has the financial strength to refund every eligible ticket immediately, unlike Qantas which does not have the liquidity to do so. This explains why there are legions of Qantas passengers not refunded even after a year," Mr Sharp said.

Qantas provides flight credits rather than refunds although in this writer's experience they were confirmed within a matter of hours of request.

Rex passengers seeking a COVID refund can access the COVID Refund portal at rex.com.au/Coronavirus/CovidBookingChanges.aspx or alternatively can go on Rex's website and click on the Rex COVID Refund Guarantee tile.