Defined Terms and Documents       

Commonwealth Bank continues the traditional treatment of charging interest (at the agreed Purchase interest rate) after the 'Payment Due Date' on the unpaid amount only - the Interest Free Period is immediately restored after the Total amount owing is repaid

Below is a monthly statement for a CBA "Diamond Awards" MasterCard which laudable/conscionable notes under 'Your payment summary' the vital information of -

*        'Payment due by'; and

*        'Total amount owing'.

Should the Cardholder not pay the entire Total amount owing by the 'Payment Due Date, the Cardholders would pay Interest at the Purchases interest rate on any shortfall until the Total amount owing is repaid.

Natasha at CBA's Help Desk 132221 at 2:10pm on Wed, 31 Dec '14 informed that should a Cardholder not pay the entire 'Total amount owing' by the Payment Due Date, then interest would be levied on only the shortfall.  The Cardholder would forfeit its 'Interest free period' until the full 'Total amount owing' was paid.  Hence, if a Cardholder had to pay $100 as the 'Total amount owing' and paid only $90, the Cardholder would be charged interest on its Purchases for $10 until that outstanding $10 had been paid.  If the Cardholder paid the outstanding $10 a week after the Payment Due Date, the Cardholder would pay interest on $10 for 7 days at the agreed interest rate for Purchases.  The Interest Free Period would be re-instated once the entire 'Total amount owing' was paid.  Hence, the Cardholder would be charged interest on any subsequent Purchases (at the agreed interest rate for Purchases) during the week, but only until the 'Total amount owing' was paid.

One ponders why CBA had bold print for 'Minimum payment due', but not 'Total amount owing'.

Alas, not all Credit Card Issuers apply the traditional treatment of charging interest (at the agreed Purchase interest rate) after the Payment Due Date on the unpaid amount only.  Usurious Unsecured Personal Loan Interest Rates Are Charged On Some Credit Cards for a minimum of three months where the Total Amount Owing/Closing Balance is not repaid 'in toto' by the 'Payment Due Date as described in -

*        Example 1 - Unconscionable Conduct - St George Visa Card

*        Example 2 - Unconscionable Conduct - Coles 'No Annual Fee MasterCard' and Coles 'Rewards MasterCard'