Can You Vary PAYG Instalments If Your Business Income Drops?

by Timothy Quinn
November 3, 2026

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Timothy Quinn Head of Tax & Accounting

Chartered Accountant Timothy Quinn leads Tax & Accounting at Lawpath. 16+ years in tax advisory, specialising in startup growth and expansion. Passionate about supporting entrepreneurial clients with early-stage investment incentives, restructuring, international exit strategy planning, and more.

? Fast facts

You can vary PAYG instalments if the current amount or rate doesn’t reflect the tax you expect to owe for the year.
How you vary them will depend on whether you’re using the instalment amount method or the instalment rate method.
If your business income drops but you’re using the instalment rate method, the amount payable will naturally change with your current income.
Use current-year forecasts rather than simply choosing a lower number.
A variation applies to the remaining instalments for the year unless it’s varied again.
Varying too low can lead to a tax shortfall and penalties.
When you lodge your tax return, PAYG instalments will be credited against the final income tax liability anyway.

PAYG instalments are prepayments towards your expected income tax liability. If your business income has dropped, your instalments may no longer match the tax you’re likely to owe. A variation may help bring them back into line, but it isn’t always the right approach.

Let’s take a look at how varying PAYG instalments work, when they apply, and what to consider.

Why are my PAYG instalments still high if business income has dropped?
When should you vary PAYG instalments?
Does varying PAYG instalments reduce your final tax bill?
PAYG instalment amount vs instalment rate: What’s the difference?
PAYG instalment variation example
What happens if you vary PAYG instalments too low?
What if your business income improves again?
Can you change from the instalment amount method to the rate method?
Is the instalment rate method better for seasonal businesses?
What is changing with Dynamic PAYG instalments?
What records should you keep when varying PAYG instalments?
PAYG variation checklist
When should you get accounting or tax advice?
FAQs

Why are my PAYG instalments still high if business income has dropped?

PAYG instalments are generally based on information from your most recently lodged tax return, rather than perfectly reflecting what’s happening in your business today. The ATO will reassess instalments after you lodge your next tax return.

Instalment amounts can also be affected by the annual GDP adjustment. For 2026–27, that GDP adjustment is 5% for relevant taxpayers using the quarterly amount method.

This can create a mismatch if:

Revenue has fallen.
Margins have tightened.
A major client has been lost.
Seasonal demand has changed.
Investment income has fallen.
A one-off profitable year inflated the prior tax result.

The ATO amount is an estimate, not a final tax assessment. It’s designed to collect tax progressively, but it may need to be varied when your tax position for the year changes.

Can you reduce your PAYG instalments?

Yes. You can vary your PAYG instalments if the amount or rate would result in paying more or less than your expected income tax for the year.

A variation can go down or up. The aim isn’t to reduce tax arbitrarily, though. The idea is to align instalments more closely with your expected final tax liability.

Do you need to vary PAYG instalments just because your income dropped?

Not always. If your business uses the instalment rate method, the amount payable already changes with the period’s instalment income.

However, if the rate itself no longer reflects your expected tax for the year, variation may still make sense.

When should you vary PAYG instalments?

Variation may be appropriate when:

Sales have fallen materially.
A major contract has ended.
The business is temporarily closed or trading less.
Investment income has reduced.
Expenses or deductions have changed the expected tax.
A previous year included an unusual one-off income.
The business expects a loss or much lower profit.

A small monthly fluctuation doesn’t automatically warrant a variation. The test is whether the existing instalment is materially out of step with your expected tax for the year.

Does varying PAYG instalments reduce your final tax bill?

No. Variation changes when tax is prepaid, not the final income-tax calculation.

When the annual tax return is lodged:

PAYG instalments already paid are credited against the final tax liability.
Excess instalments are refunded.
Any shortfall becomes payable.

PAYG variation changes the prepayments, not the tax ultimately owed. It’s essential to make sure that your BAS lodgement, PAYG variations, and final tax bill all align.

PAYG instalment amount vs instalment rate: What’s the difference?

It’s important to understand the rates and methods. Here is a quick overview:

Method	How it works	When variation may help
Instalment amount	The ATO gives you a dollar amount to pay.	Your current-year tax is expected to be materially different from the ATO amount.
Instalment rate	You apply an ATO rate to your current instalment income.	The rate itself no longer reflects your expected tax.

For the rate method, the ATO calculates the instalment using: instalment income × instalment rate. So, a varied rate can sometimes be helpful.

How do you know which PAYG method you are using?

Check your latest business activity statement (BAS) or instalment notice.

If you’re using the rate method, your BAS will include an instalment rate at T2. If there is no instalment rate at T2, you’re using the instalment amount method instead.

How do you change the PAYG instalment amount?

A variation should be based on an updated estimate of the tax you expect to pay for the full income year. Follow these steps to determine the correct rates:

Review your current year-to-date business and investment income.
Forecast income for the remainder of the year.
Estimate the expected tax for the year.
Take into account PAYG instalments already paid.
Calculate an appropriate remaining instalment amount.
Lodge the variation by the relevant due date.

The ATO provides a PAYG instalment calculator to help estimate a new amount or rate.

How do you vary the PAYG instalment rate?

If you use the rate method, follow these steps:

Estimate the instalment income for the year.
Estimate tax on that income.
Calculate a new varied rate.
Enter the varied rate at T3.
Enter the reason code at T4.

The basic formula is: estimated tax ÷ estimated instalment income × 100.

If your estimated instalment income is zero, the rate can be varied to zero.

Can you vary PAYG instalments to zero?

Yes, if your estimate supports it.

For example, a taxpayer using the rate method can vary the rate to zero if the estimated instalment income for the year is zero.

However, just because your income is down, don’t enter zero. You should have a reasonable basis for the estimate.

PAYG instalment variation example

A business had a strong previous year and received a quarterly PAYG instalment of $12,000.

This year, revenue is down substantially, and a major contract has ended, resulting in much lower projected profits. The business updates its forecast and estimates that its full-year tax liability will be significantly below the amount implied by the existing instalments.

In this case, the business should use an updated full-year forecast and the ATO PAYG instalment calculator to determine the amount. It wouldn’t be appropriate to simply reduce the next instalment by an arbitrary percentage.

What happens if you vary PAYG instalments too low?

The purpose of variation is to make a reasonable estimate, not simply defer tax.

If the variation is too low relative to the eventual tax liability, the business may:

Face a larger tax bill when the return is lodged.
Have less cash available to pay the shortfall.
Potentially face PAYG variation penalties or interest if the estimate was insufficient under the applicable rules.

It’s best to review your expected tax regularly and vary instalments as needed to avoid penalties.

What if your business income improves again?

You should reassess the variation. Once you vary the amount or rate, that calculation will apply for the rest of the financial year unless you make another variation.

If your income significantly improves:

Update the forecast.
Reconsider the variation.
Increase later instalments where appropriate.

This avoids turning one weak quarter into an unrealistic full-year estimate. Tax planning services can help ensure a realistic forecast.

Can you change from the instalment amount method to the rate method?

This is separate from varying an instalment. You can change your PAYG instalment option only at the beginning of the relevant financial year, before the first BAS or instalment notice is due.

The key distinction is:

Variation changes the amount or rate within the current method.
Changing the method changes how instalments are calculated and is subject to separate timing rules.

Is the instalment rate method better for seasonal businesses?

The instalment rate method may suit a fluctuating income because each instalment changes with income for that period.

It can be particularly relevant for seasonal businesses, such as tourism operators, seasonal retailers, event businesses, and agricultural businesses. However, whether it is better depends on the business’s income pattern, tax position and reporting needs.

What is changing with Dynamic PAYG instalments?

The Government announced Dynamic PAYGI in the 2026–27 Budget so that PAYG variations can respond more quickly to current business performance. The new rules will take effect from 1 July 2027.

The proposal also includes:

Allowing businesses to opt into monthly PAYG instalment reporting.
Requiring monthly reporting for taxpayers with a demonstrated history of non-compliance.

Remember that this isn’t a law yet and hasn’t come into force.

What does Dynamic PAYGI mean for businesses?

The intended benefit is that instalments could better reflect:

Current sales
Current expenses
Current profitability
Changing business conditions

This is instead of relying heavily on historical tax return data. This directly addresses the problem that traditional PAYG instalments can lag what is happening in the business.

What records should you keep when varying PAYG instalments?

Keep enough evidence to show the variation was based on a reasonable current-year estimate. This includes:

Year-to-date management accounts
Sales reports
Profit and loss statement
Cash-flow forecast
Updated full-year income estimate
Tax estimate
PAYG instalment calculator output
BAS or instalment notices
Records explaining why the variation was made
Later revisions to the forecast

PAYG variation checklist

Confirm whether you use the instalment amount or the rate method.
Review current year-to-date business and investment income.
Forecast the remainder of the financial year.
Estimate expected full-year tax.
Review PAYG instalments already paid.
Use the ATO PAYG instalment calculator.
Calculate the revised amount or rate.
Lodge the variation by the instalment due date.
Keep evidence supporting the forecast.
Reassess later if business conditions change.
Increase instalments again if performance improves materially.
Do not confuse varying an instalment with changing calculation methods.

Before reducing instalments, make sure a realistic current-year tax forecast supports the variation.

If your instalments no longer reflect current performance, tax or accounting advice can help you prepare that forecast.

When should you get accounting or tax advice?

Get accounting and tax advice when:

The business has experienced a large or sudden fall in income.
Profit has changed more than revenue.
The business expects a tax loss.
Several entities are involved.
The existing instalment appears materially too high.
There are significant capital gains or investment income.
The business is considering varying to zero.
Previous PAYG variations have resulted in tax shortfalls.
Cash-flow pressure is driving the decision rather than an actual change in expected tax.

Lawpath can help you ensure business tax compliance, no matter what stage your business is at. Get in touch with our team of professional legal advisors and registered BAS agents to get your taxes right.

FAQs

Can you reduce PAYG instalments if business income drops?

Yes, if the current instalment amount or rate doesn’t reflect the tax you expect to owe for the year. The variation should be based on a realistic full-year forecast, not simply on a lower recent sales figure.

How do I vary my PAYG instalments?

First, identify whether you use the instalment amount or the rate method. Then estimate your full-year tax position, use the ATO PAYG instalment calculator, and lodge the varied amount or rate by the relevant due date.

Can I vary PAYG instalments to zero?

Yes, but only if your estimate supports it. For the rate method, the ATO says you can vary the rate to zero if your estimated instalment income for the year is zero.

What is the difference between the PAYG instalment amount and the instalment rate?

The instalment amount method uses a dollar amount set by the ATO. The instalment rate method applies an ATO rate to your current instalment income, so the payment changes with income.

Do I need to vary my PAYG rate if my income drops?

Not necessarily. If you use the rate method, your instalment already rises or falls with your income.

Can I change my PAYG instalment method mid-year?

Generally, no. The ATO says you can change your instalment option only at the beginning of the relevant financial year, before the first BAS or instalment notice is due.

What happens if I vary PAYG instalments too low?

You may have a larger tax bill when you lodge your return, and you may face penalties or interest if a reasonable estimate didn’t support the variation.

Does varying PAYG instalments reduce my tax bill?

No. It changes the timing and amount of your prepayments, not your final income tax liability. Instalments paid are credited when you lodge your tax return.

What happens if my income increases after I vary PAYG instalments?

You should reassess your forecast and consider varying again.

How long does a PAYG variation last?

It generally applies to the remaining instalments for that financial year, unless you make another variation.

What is Dynamic PAYGI?

Dynamic PAYGI is a proposed reform announced in the 2026–27 Budget to make PAYG instalments respond more quickly to real-time business conditions from 1 July 2027.

Will businesses be able to pay PAYG instalments monthly from 2027?

Businesses may be able to opt in to monthly PAYG instalment reporting under the proposed reforms. However, the optional monthly reporting measure is not yet law.