Using the voucher system when paying an invoice outside the discount period, assuming the gross method, the entry would be to debit Vouchers Payable, credit Sales Discounts, and credit Cash.

Sales Discounts

Reductions in the price of goods sold, offered to customers as an incentive to either prompt payment or increase sales volume.

Vouchers Payable

Liabilities or debts owed by a company for purchases made on credit, documented by vouchers.

Gross Method

An accounting practice where purchases are recorded at their full invoice amount without deducting any purchase discounts.