PAYG Instalments, Explained: It's Not Extra Tax — It's Your Tax, Paid Early

If a letter from the ATO has just told you that you're now in "PAYG instalments," take a breath. This is one of the most misread parts of the Australian tax system — and the misreading almost always runs in the scary direction. So let's start with the single most important fact:

PAYG instalments are not an extra tax. They are pre-payments of the income tax you were always going to owe — collected in instalments through the year, then credited in full against your final bill. Pay a little more than your actual tax? You're refunded the difference. Pay a little less? You top it up. Either way, the total tax is the same. The only thing that changes is the timing — and used well, that timing works in your favour.

Here are the ten questions we get asked most, answered for the 2026–27 financial year.

1. Why did the ATO suddenly put me on instalments — and is it extra tax?

The ATO looks at your most recent tax return. If it shows you earning a decent amount of business or investment income and paying a decent amount of tax, the ATO reasonably assumes you'll do the same again this year — and rather than let a big bill build up to a single nasty lump at tax time, it asks you to pre-pay in instalments as you go. Employees have tax taken out of every pay (that's PAYG withholding); PAYG instalments do the same job for income that doesn't have tax withheld — business profit, rent, dividends, interest.

What happens at tax time (the part that removes the fear): every instalment you pay is recorded as a credit. When you lodge, your instalment credits are subtracted from your assessed income tax. If your instalments added up to more than your actual tax, the excess is refunded. If they added up to less, you pay the shortfall. You are never taxed twice — you're simply paying this year's tax in four pieces instead of one.

2. Who actually has to pay them?

This is where getting your legal category right matters — the tests are different for individuals and companies, and it's easy to blur them.

Individuals, sole traders and trusts are automatically entered when all three of these are true, based on your latest return and notice of assessment (FY2026–27):

•  Instalment income of A$4,000 or more — your gross business and investment income (excluding GST and, generally, capital gains);

•  Tax payable of A$1,000 or more on your latest notice of assessment; and

•  Notional tax of A$500 or more (the ATO's estimate of your tax on that income).

Companies and super funds use a different test — there's no $4,000/$1,000 income hurdle. A company is generally brought in once its notional tax is A$500 or more. And a company or fund with instalment income of A$2 million or more is generally required to report and pay monthly rather than quarterly.

You don't opt in — the ATO notifies you once you cross the line. (These are the current-year figures; your adviser should confirm them against your specific facts before you rely on them.)

3. My income has dropped — can I lower my instalments?

Yes — and this is the most valuable lever in the whole system. If your instalment is based on last year's strong result but this year is quieter, you don't have to keep pre-paying tax you won't owe. You can vary your instalment down on your activity statement or instalment notice (you enter a reason code, and the varied figure applies for the rest of the income year). That keeps cash in your business instead of parked with the ATO until your refund.

The guard-rail — the 85% safe harbour. When you vary, you're estimating your full-year tax, so don't be too aggressive. If your total instalments for the year come to at least 85% of your actual tax liability, no interest applies. Drop below 85% and the ATO can charge the General Interest Charge on the shortfall. The ATO has also flagged its compliance approach to excessive downward variations (draft guidance PCG 2026/D3), so vary to a genuine, defensible estimate — not wishful thinking.

Rule of thumb: it's fine to vary when your income has genuinely changed; aim for a realistic full-year estimate, and keep it at or above 85% of what you'll really owe.

4. Instalment "amount" vs instalment "rate" — which method?

The ATO offers two ways to work out each instalment:

•  Option 1 — the instalment amount. The ATO gives you a fixed dollar figure (pre-filled on your statement), worked out from your last return and uplifted by the GDP factor. Simplest option — you just pay it. Best when your income is fairly steady; vary it only if things change materially.

•  Option 2 — the instalment rate. The ATO gives you a rate (%) and you apply it to your actual business and investment income for the quarter. Your payment rises and falls with your income automatically, so there's far less need to vary. Best for lumpy or seasonal income.

About that uplift: the instalment-amount method bakes in a GDP adjustment factor to estimate income growth. For FY2026–27 it's 5% (up from 4% in FY2025–26). It only affects the amount method — if you use the rate method or pay annually, the GDP uplift doesn't touch you.

5. When are they due?

Most payers are quarterly:

Quarter	Period	Due
Q1	Jul–Sep	28 October
Q2	Oct–Dec	28 February
Q3	Jan–Mar	28 April
Q4	Apr–Jun	28 July

Smaller taxpayers who are eligible (generally those not registered for GST) can choose to pay a single annual instalment, due 21 October. If you want annual, you generally need to elect it by the 28th day after your first instalment quarter.

6. Sole trader vs company — how do instalments differ?

They feel similar but sit on different taxpayers:

•  Sole trader: the instalments pre-pay your personal income tax. Your business profit is taxed at your individual marginal rates alongside your other income (salary, rent, and so on), and entry uses the individual $4,000 / $1,000 / $500 test.

•  Company: the instalments pre-pay the company's income tax at the flat company rate. The company is a separate legal taxpayer with its own return; entry is on notional tax of $500 or more, and $2M+ instalment income means monthly payments.

Keeping the two straight matters — a director paying themselves a wage can have both a company on instalments and their own personal instalments, and they're not the same obligation.

7. I have rental or investment income — will I be put on instalments?

Quite possibly. "Instalment income" isn't just business income — it includes gross rent, dividends, interest and trust distributions. So a salaried employee who has a strong year from an investment property or share portfolio can be automatically entered once the $4,000 / $1,000 / $500 thresholds are met, even without running a business.

Two useful exclusions: capital gains and GST are left out of instalment income. So a one-off capital gain on selling an asset doesn't, by itself, drag your ongoing instalments up the way recurring rent or dividends can.

8. At tax time, do instalments top up my bill or get refunded?

This is really question 1 seen from the other end, and it's worth repeating because it's where the worry dissolves. Your instalments are credits. At lodgment:

•  Instalments > actual tax → you're refunded the excess (or it offsets other liabilities);

•  Instalments < actual tax → you pay the difference.

There's no double tax and no lost money — just a reconciliation. The instalments simply mean you arrive at tax time having already paid most (or all) of the bill.

9. Can I get off the list — and when does the ATO take me off?

Yes. The ATO automatically removes you when your latest return no longer meets the entry thresholds — for example, your business winds down or your investment income falls away. You can also ask to be withdrawn if you no longer meet the criteria, or consolidate to annual reporting if you're eligible. If you exit part-way through a year, any instalments you've already paid still count as credits on your next return — nothing is wasted.

10. What if I don't pay, or I vary it wrong?

Two costs to know about — and one of them just got more expensive.

•  Unpaid or late instalments attract the General Interest Charge (GIC), which compounds daily. The rate resets each quarter; for the current July–September 2026 quarter it's 11.43% p.a. (up from 10.96% the previous quarter).

•  Varying below the 85% safe harbour exposes the shortfall to GIC as well (see question 3).

And the change that stings: GIC is no longer tax-deductible for income years starting on or after 1 July 2025. Carrying an ATO debt used to be softened by a deduction — now it isn't, so the real cost of paying late is higher than it looks. The takeaway: pay on time, and if your income has genuinely dropped, vary rather than simply skip.

The bottom line

PAYG instalments aren't a new tax and they aren't a penalty — they're your own income tax, paid in sensible pieces through the year and reconciled to the cent when you lodge. Get on top of two things and the system works for you: choose the method that fits your income (steady → amount; lumpy → rate), and vary honestly when your income changes (staying at or above 85%). Do that, and instead of a year-end shock you get smooth cash flow and no surprises.

Figures are for the 2026–27 financial year and are general information, not personal tax advice. Thresholds, rates and the GIC change over time — confirm the current-year numbers for your own situation, or ask us and we'll check them with you.