GST for sole traders: a practical starting point

Keep three ideas separate

Your ABN identifies your business activity. GST registration is a separate status. Income tax is another obligation, generally concerned with taxable income. Having an ABN does not make every invoice a tax invoice, and GST collected is not simply extra profit.

Check the official guidance on registration first. Then decide whether a particular supply is taxable, GST-free or input-taxed. A calculator can only apply the assumption you give it.

A pricing example

Suppose you want to charge $400 before GST for a fully taxable job while registered. The customer pays $440 and the GST component is $40. If you promise a fixed $400 GST-inclusive total instead, that total contains $36.36 GST and leaves $363.64 before GST.

Those are different commercial prices. Decide what you intend before quoting. Write the tax basis clearly so you and the customer are discussing the same final amount.

Build a repeatable admin routine

1. Record each sale with a recognisable reference and description.
2. Keep supplier invoices and distinguish business from private expenses.
3. Review registration status and turnover as the business changes.
4. Check the GST basis and treatment before producing a document.
5. Save the final PDF and relevant correspondence in your own records.

Use the quote maker to set out proposed work, then an invoice when requesting payment. A receipt records payment already received.

Understand the tools’ limits

CalcGST does not calculate income tax, decide GST-credit eligibility or lodge a business activity statement. A bank transaction can also contain transfers, loan movements or mixed items, so it is not always equivalent to a taxable sale.

Seek tailored help when your business has overseas customers, property transactions, mixed activities or a change in registration date. A simple tool is most useful when the underlying transaction is already understood.

Common questions