The Admiralty Warrant of 4 June 1903 authorised the Australian Red Ensign for vessels registered in Australia. In 1932 it was determined that the majority of private non-commercial vessels, were not registered, and as such were subject to a substantial fine under British statue if they did not fly the British Red Ensign. An Admiralty Warrant of 5 December 1938 replaced the 1903 order thereby mandating that all ships and boats owned by British subjects in Australia and New Guinea to fly the Australian Red Ensign.

Initially, the Red Ensign was the only flag private citizens could fly on land. In 1941 Prime Minister Robert Menzies lifted the restriction on flying the Australian Blue Ensign. In 1953,Parliament passed the "Flags Act" which reversed the rules authorising only the Blue Ensign for citizen use on land and prohibiting use of the Red Ensign except at sea. The current Shipping Registration Act of 1981 permits an Australian merchant vessel to only fly the Australian Red Ensign. Other Australian vessels may choose to fly either the Australian Red Ensign or the Australian National Flag, but not both at the same time.

Flag Measures 36 in x 60 in and is 100% polyester with grommets for easy flying.