Our OsCommerce invoices are being produced with the wrong Tax amount. The tax amount is set to 17.5% but it is taking this amount away from the product amount excluding tax. Instead of taking it away form the product amount including tax.
Product cost: $100
OsC is taking 17.5% from $82.5 then displaying its result, and the tax amount.
It should look like this.
Cost Inc. $100
Cost Exc: $82.50
Tax amount: $17.50
Please can someone sort this for us.