Free tool

Tax set-aside calculator

Enter what a customer just paid you and your usual profit margin, and see how much of it to move aside: the GST (if registered) and a reserve for income tax on the profit portion. A rule of thumb, not your tax bill.

25 to 30 is a common starting point; adjust after your first return.

Move aside from this payment

GST to hold for BAS
$200.00
Income tax reserve
$324.00
Total to set aside
$524.00
Yours to spend or reinvest
$1,676.00

Estimated profit on this payment: $1,200.00. This is a set-aside rule, not your tax assessment.

General information, not tax advice. Confirm current rates and dates on ato.gov.au. Read the guide: tax set aside sole trader tradie.

Common questions

Why is it a percentage of profit, not the payment?+

Income tax is on profit: income minus deductible expenses. If a third of what you invoice goes on materials, the tax is on the other two-thirds.

What reserve percentage should I use?+

25 to 30 percent of profit covers most sole traders under the tax-free threshold plus a couple of brackets. Higher earners should use more. Your first tax return tells you the real rate.

What about PAYG instalments?+

Once the ATO puts you on instalments, you are paying this reserve to them quarterly. Keep setting it aside and use it to pay the instalments.

Other tools: GST calculator · BAS due dates

SmokoBooks does this every day, from your real invoices.

GST position, BAS by quarter and a tax set-aside estimate on the dashboard, worked out from what you actually invoiced and spent. From $19 a month.