Businessman Alan Thiess has lost more than half a million dollars in customs duty and GST he mistakenly paid when he imported a new yacht.
The High Court has ruled he can't get the money back.
The Customs Act bars all actions for recovery of duty paid to Customs, except in a couple of narrow exceptions, the court ruled on Wednesday.
Judges said the legislation was drafted that way to ensure those liable for customs duty were vigilant and to object within six months if they believed the assessment was incorrect.
Mr Thiess' problem arose in 2004 when he arranged to buy a luxury Sunseeker 108 yacht for STG4,254,500 ($A7.69 million). He named the vessel SoulSeeker.
But his customs agent mistakenly believed the vessel's gross weight was 108 tonnes, which made Mr Thiess liable for customs duty of $A494,472, with an additional $A49,447 payable as GST.
He duly paid and took delivery.
In fact the yacht weighed more than 150 tonnes, which made it duty free.
Only in October 2006, well past the statutory period for seeking a refund, did Mr Thiess learn he should not have paid any duty.
He applied to get his money back and was refused, embarking on protracted litigation which concluded in the High Court on Wednesday.
Judges dismissed his appeal, ruling the customs legislation was quite emphatic in barring any recovery action outside the six-month period.
