Your business has all sorts of income types. On some of the income, you may collect a tax from a customer, or the income source provider. For example, in Australia, items such as medication, education, fresh fruits and vegetable are tax free (at least until 2017). So if you sell a products or service in this item category, you do not collect a tax from the customer, so you are not required to pay it back to the tax office. But if for example you were selling cloths, they do attract a Goods and services tax which your customer pays you. So on some products and services, you are collecting a tax, and on some you are not. If you collect a tax from the customer, you will need to pay this to the tax department on your activity report. It is imparative that you make sure that the income type is set up as Taxable or Tax Free.