Quick answer
To plan for BAS, treat GST collected and PAYG withheld as the ATO's money from the moment you receive it. Move it into a separate holding account each week, forecast BAS due dates in your cash flow, and keep pricing high enough to carry tax. If a shortfall appears, lodge on time anyway, contact the ATO about an arrangement, and consider whether finance is appropriate.
Key points
- GST and PAYG withheld are not your working capital.
- A weekly transfer to a tax holding account prevents surprises.
- Lodge on time even if you cannot pay in full.
- Forecast BAS dates alongside wages and suppliers.
Checklist
- Separate tax holding account set up
- Weekly GST and PAYG transfers scheduled
- BAS due dates in the forecast
- Super payments planned for Payday Super
- Pricing reviewed to carry tax
The quarterly BAS is one of the most predictable bills a business faces, yet it causes more cash flow stress than almost anything else. The reason is simple: GST and PAYG withholding arrive in your account mixed in with everything else, and in a busy quarter they quietly get spent on wages, stock and suppliers. When the BAS falls due, the money has gone. Planning for BAS is mostly about stopping that from happening.
Whose money is it?
GST you charge customers and PAYG you withhold from wages are collected on behalf of the ATO. They pass through your account, but they are not your working capital. Treating them as the ATO’s money from the moment they arrive is the mindset shift that prevents most tax debts.
The holding account habit
Open a separate bank account for tax. Each week, transfer:
- the estimated net GST (GST on sales less GST credits on purchases);
- PAYG withheld from that week’s wages;
- any PAYG instalments you expect.
When the BAS is due, the money is already there. Many accounting systems can estimate the weekly figure. The ATO’s GST and PAYG withholding pages explain the obligations.
Forecast the dates
Put BAS due dates into your cash flow forecast alongside wages, rent and supplier payments. The ATO’s BAS pages list lodgement and payment dates. With Payday Super from 1 July 2026, super now goes out close to each payday, so plan it with wages rather than with BAS. The cash flow gap calculator lets you include tax months.
Monthly versus quarterly
Some businesses find monthly BAS reporting easier because amounts are smaller and the gap between collecting and paying is shorter. Others prefer quarterly. If quarterly bills keep catching you out, ask your accountant whether switching makes sense.
Pricing that carries tax
If the business only stays afloat by spending tax money, pricing or costs need attention. Check that quotes and prices properly account for GST and that margins are sufficient after all costs. Finance cannot fix a pricing problem.
If a shortfall appears
| Step | Why |
|---|---|
| Lodge on time | Keeps options open and matters for director penalties |
| Contact the ATO | Discuss a payment arrangement early |
| Review cash flow | Find the cause and the timing |
| Consider finance | Only if it fits and the cause is being fixed |
| Talk to your accountant | Tax and structure advice |
For companies, unpaid PAYG and GST can become personal director liabilities; see our guide to director penalty notices.
Where finance fits
A line of credit can bridge a short gap between a BAS due date and a large customer payment. If a larger ATO debt has built up, compare a payment plan with an ATO tax debt loan using our guide to ATO payment plans versus loans. Whichever route, set up the holding account habit so the next quarter is different.
An illustrative example
A made-up landscaping business has scrambled every quarter for two years. The owner opens a tax account and sets an automatic weekly transfer based on the accounting system’s GST and PAYG estimate. The next BAS is paid in full from that account without touching the operating account, and the line of credit that used to cover BAS sits unused.
Getting the GST estimate right
The weekly transfer works best when the estimate is close to reality. Use your accounting software’s GST report rather than a rough percentage of sales, because GST-free sales, input-taxed items and GST credits on purchases all change the net figure. Reconcile the holding account against the actual BAS each quarter. If the account consistently ends with too much or too little, adjust the weekly transfer.
What to do with a surplus
If the tax account ends a quarter with a small surplus after paying the BAS, leave it there as a buffer for the next quarter or for income tax. A buffer turns the tax account from a scramble into a routine.
Income tax and instalments
BAS is not the only tax that arrives in a lump. PAYG instalments on business income and the annual income tax bill can also catch owners out, especially in a year when profit grows. Ask your accountant to estimate them and add a weekly amount to the tax account so they are covered too.
When cash is tight across the board
If the business genuinely cannot afford to set money aside, that is important information. It may mean prices are too low, costs too high or the business is carrying debts it cannot service. Talk to your accountant before the next BAS rather than after it.
Need help with a tax-time gap?
If BAS has already caught you short, or you want a buffer while you set up better habits, make one enquiry. There is no credit check when you first enquire, a real person reviews it and your details go to one lending partner rather than a list. Tell us the BAS amount and due date in your enquiry.
Frequently asked questions
How much should I set aside for GST?
Set aside the GST included in your sales, less GST credits on business purchases, as you go. Your accounting software or accountant can estimate the net amount each week.
What happens if I can't pay my BAS?
Lodge on time anyway and contact the ATO about payment options. Lodging keeps options open and, for companies, affects director penalty exposure.
Should I lodge BAS monthly or quarterly?
It depends on your turnover and preferences, within ATO rules. Some businesses find monthly reporting easier to manage because amounts are smaller and more frequent.
Is it OK to use GST money for wages in a tight month?
It is common but risky. The BAS still has to be paid, and using tax money as working capital is a frequent cause of ATO debt.
Can finance help with BAS?
A line of credit can bridge a short timing gap, and some lenders lend to clear ATO debt. Compare with an ATO payment plan and fix the cause.
Do I need a separate bank account for tax?
It is not required, but it is one of the most effective habits for avoiding tax shortfalls.
How does Payday Super affect BAS planning?
Super now needs to be paid close to each payday rather than quarterly, so plan super alongside wages rather than with BAS.
Can my bookkeeper manage the tax account?
Yes. Many businesses ask their bookkeeper to make the weekly transfer and reconcile the account each quarter. Make sure you still review it so you know the tax is covered.
Sources and further reading
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