Commonwealth Bank of Australia v McArthur

The Commonwealth Bank of Australia sought repayment and possession of residential property held under a Torrens title, which had been provided as security for loans made to a corporate borrower. The borrower was a director and shareholder of a company which had taken out a loan secured by a third-party mortgage over the property. The bank claimed the mortgagor, who had guaranteed the corporate borrower’s obligations under the loan agreement, was liable for the outstanding debt due to the bank's registration of a third-party mortgage over the property. The mortgagor argued that the loan agreement had been varied in a way that materially prejudiced their interests, which would discharge the guarantee.

The court was required to determine whether the loan agreement had been varied in a manner that prejudiced the interests of the surety, thereby discharging the guarantee. Additionally, the court needed to ascertain whether the revised loan agreement constituted a material variation of the original contract, which would affect the enforceability of the guarantee. The court also needed to examine if the bank's conduct in enforcing the guarantee against the mortgagor was unconscionable, considering the mortgagor's claims of ignorance about the financial affairs of the debtor company and the terms of the loan agreement.

The court held that the revised loan agreement was an independent contract and not a variation of the original agreement. The mortgagor was aware of the condition attached to the original loan offer, which was dependent on a satisfactory valuation of the security property. When the valuation did not meet the bank's requirements, the original offer was withdrawn, and a revised offer, which was more onerous and entailed greater business risk, was presented. The mortgagor accepted the revised terms, and there was no evidence of misrepresentation or mistake about the nature of the transaction. Therefore, the guarantee remained enforceable. Furthermore, the court found that enforcing the guarantee did not constitute unconscionable conduct, as there was no misrepresentation or mistake on the part of the bank, and the mortgagor was not mistaken about the effect of the transaction.

The final orders of the court were that the Commonwealth Bank of Australia was entitled to repayment of the outstanding debt and possession of the mortgaged property. The guarantee provided by the mortgagor remained valid and enforceable, and the claim for unconscionable conduct was dismissed.