PAYG Withholding vs PAYG Instalments: Know the Difference

These two have almost identical names and are constantly confused, but they do completely different jobs. PAYG withholding is tax you hold back from other people — mainly your employees — and pass to the ATO on their behalf. PAYG instalments are prepayments of your own income tax on the profit your business makes. Mixing them up leads to under-remitting one and being surprised by the other, so it's worth getting the distinction clear.

PAYG withholding: tax you collect for others

When you pay wages, you withhold an amount of tax from each employee's pay and send it to the ATO. That money was never yours — it's your employee's tax, and you're the collection agent. Withholding also applies in some other situations: payments to contractors who haven't quoted an ABN, and certain payments to other businesses.

The mechanics run through Single Touch Payroll: each pay run, your payroll software reports the wages and the tax withheld to the ATO. You then remit the withheld amounts according to your reporting cycle, and the totals flow through to your activity statements. The critical mental model is that withheld tax is held in trust — it isn't working capital. Businesses get into serious trouble when they treat the withholding sitting in their account as spare cash and then can't remit it when it's due.

PAYG instalments: prepaying your own tax

PAYG instalments are how you pay your own income tax progressively through the year rather than in one lump after you lodge your return. The ATO generally puts you into the instalments system once you've reported business or investment income above a certain level on a lodged return. From then on you pay instalments — usually quarterly — towards the tax you expect to owe on this year's income.

The point is cash-flow smoothing for both sides: you're not hit with a large bill at year end, and the ATO collects steadily. When you lodge your return, your total instalments paid are credited against your actual tax liability. If you paid too much across the year, you get the excess back; if you paid too little, you top up the difference.

How the ATO works out your instalment

You'll generally be offered two methods:

• The instalment amount — the ATO calculates a dollar figure for you based on your most recently lodged return, and you simply pay it. Simplest, but it doesn't react to how your business is actually tracking this year.
• The instalment rate — the ATO gives you a percentage, and you apply it to your actual income for the quarter. This flexes with your real trading, so it's better if your income is variable or has dropped.

You can vary your instalments if your circumstances have changed — for instance, if profit is well down on last year and the ATO's figure is based on a stronger prior year. Varying is legitimate, but if you deliberately underestimate and end up well short, general interest charges can apply. Vary on a genuine, reasonable estimate, not on optimism.

Where they meet: your activity statement

Both typically appear on your activity statement — the BAS or IAS. Withholding shows as the tax you've collected from employees and must remit; instalments show as the prepayment of your own income tax. On a single statement you might be paying both: the tax you held from staff, plus an instalment towards your own liability. Reading the statement carefully so you know which line is which is half the battle, because they're funded from different places conceptually — one is money you were only ever holding, the other is your own tax.

Practical steps to stay on top of both

• Keep withheld PAYG separate in your thinking, and ideally set it aside — treat it as already spent the moment you run payroll.
• Make sure your STP reporting is going through cleanly each pay run; that's what feeds the withholding side.
• Diarise your instalment due dates and decide which method suits your income pattern.
• Review your instalments if your profit shifts materially, and vary on a defensible estimate rather than being carried by last year's numbers.
• Reconcile at year end so you understand whether you'll receive a credit or owe a top-up, and can plan cash for it.

For how tax obligations like these fit into a back office that runs without constant firefighting, see our Finance hub.

This is general information, not tax advice. Thresholds, rates, and how the PAYG systems apply to you depend on your circumstances — check the ATO's current guidance or speak to your registered tax agent or BAS agent.