PAYG Instalments for the Self-Employed, Explained
Why the ATO asks you to pre-pay tax — and how to avoid the year-one cash-flow trap
The first time a sole trader sees "PAYG instalment" on an ATO notice, the reaction is usually panic — it looks like you're being asked to pay tax twice. You're not. But the timing catches thousands of people out, and getting it wrong creates a cash-flow hole right when a young business can least afford it.
General information only, not personal tax advice. Verify current thresholds and rules with the ATO (ato.gov.au).
What PAYG instalments actually are
As an employee, your employer withholds tax from each pay and sends it to the ATO. As a sole trader, no one does that for you — so you'd otherwise face one enormous tax bill after lodging. PAYG instalments are simply the ATO's way of collecting your income tax gradually across the year, usually in quarterly amounts, instead of all at once.
It's a pre-payment toward your expected tax bill. When you lodge your return, your actual tax is calculated and the instalments you've already paid are credited against it. Pay too much across the year and you get the difference back.
Why you got put on it
The ATO automatically enters you into PAYG instalments once you report business or investment income above certain thresholds in your tax return (verify the current entry thresholds). So it typically shows up in your second year of self-employment — after your first return revealed you owe tax that wasn't being withheld.
This is the classic year-one trap: in your first year you pay your whole tax bill in one hit at lodgement and may start instalments for the next year at the same time. Two obligations landing together. Knowing it's coming is half the battle.
How the amount is worked out — and how to change it
The ATO offers two ways to calculate each instalment:
- Instalment amount: a fixed dollar figure the ATO works out from your last return. Easiest.
- Instalment rate: a percentage you apply to your actual income for the quarter — better if your income varies a lot, because you pay in line with what you actually earned.
If your income has dropped (or jumped), you can vary your instalment so you're not over- or under-paying. Be careful: vary it too low and you can face interest if you end up underpaying significantly.
How to stay ahead of it
- Set aside tax from day one. A common rule of thumb is to park roughly 25–30% of profit (your actual rate depends on income — get advice) so the money's there.
- Treat instalments as the tax you already owe, not an extra cost — paying them just means a smaller (or nil) bill at lodgement.
- Vary down if income falls, so you're not financing the ATO unnecessarily.
- Diarise the quarterly due dates.
How TaxBot helps
TaxBot tracks your income and deductible expenses as you go, so you always have a live picture of your likely profit — and how much to set aside for tax and instalments. No year-end shock, no scrambling to find the cash.
The takeaway
PAYG instalments aren't a new tax — they're the same tax, paid in sensible pieces. Set money aside as you earn, keep an eye on whether your instalment still matches reality, and the system works in your favour for cash flow.