Campbell v Kitchen & Sons Ltd and Brisbane Soap Co Ltd

The Supreme Court of Queensland considered a dispute between the plaintiff, Campbell, and the defendants, Kitchen & Sons Ltd and Brisbane Soap Co Ltd. The core of the dispute concerned an agreement under which Campbell acted as a del credere agent for the defendants, selling their goods. A key element of the arrangement involved a trade usage whereby Campbell was entitled to a discount on goods sold, which was to be deducted from the amounts he remitted to the defendants. The plaintiff alleged that he had mistakenly paid the full amounts without deducting this discount, and sought to recover the overpaid sums.

The court was required to determine whether the plaintiff was entitled to recover the amounts paid in excess of what was due under the del credere agency agreement. Specifically, the court had to consider the legal effect of the trade usage regarding the discount, whether the plaintiff's payment constituted a voluntary payment made under a mistake of law, and if so, whether such a payment was recoverable. The court also had to assess whether the accounts between the parties had been settled in a manner that precluded the plaintiff from raising this claim.

The court found that the del credere agency agreement, incorporating the established trade usage, entitled the plaintiff to a discount on the goods sold. The plaintiff's payments without claiming this discount were made under a mistake of law, as he was unaware of his legal right to deduct the discount. The court applied the principle that money paid under a mistake of law is generally not recoverable, however, it distinguished this situation by finding that the plaintiff's payments were not truly voluntary in the sense that they were made in ignorance of his legal rights and obligations arising from the contract and trade usage. The court held that the plaintiff was entitled to recover the sums paid in excess of the amounts properly due after the deduction of the agreed discount.