Most Australian SMEs hold either too little cash, in which case they panic at every revenue dip, or too much, in which case they starve growth and leave returns on the table. There is a real number for each business, and it has shifted in 2026. With the RBA cash rate at 4.10%, business savings accounts paying meaningful interest again, and Payday Super starting 1 July 2026 removing the quarterly super float that many businesses have used as working capital, the calculation is materially different from what it was even 18 months ago.
Published: April 2026
A cash reserve is the amount of liquid funds a business holds outside its day-to-day operating account specifically to cover unexpected cash gaps. It is not the same as working capital, which is the cash needed to fund the normal operating cycle. It is not the same as a sinking fund for tax or super, which is money already earmarked for known obligations. A cash reserve is genuinely uncommitted, accessible within a few days, and held against shocks: revenue drops, customer losses, equipment failures, or compliance surprises.
The right cash reserve is large enough that the business can absorb a realistic shock without panicked decisions, and small enough that capital is not sitting idle when it could be deployed.
Both ends of the spectrum kill businesses, just on different timelines.
Too little cash. The business is profitable but operates with one to two weeks of cash in the bank. Every late-paying customer triggers a payroll scramble. Every unexpected expense becomes a crisis. Decisions get made under pressure, which means they get made badly. Customers can sense it, and the best ones quietly find alternative suppliers. This is the modal failure pattern for Australian SMEs, with 15-27% of SMEs reporting minimal or no cash buffer as recently as 2025.
Too much cash. The business is sitting on six to twelve months of operating expenses in cash, returning whatever the bank pays on a business savings account. Growth is slower than it should be because capital is not being deployed into hiring, marketing, or product. The owner knows the business could grow faster but cannot get comfortable spending the buffer.
The right answer is between these. The framework below tells you where.
The traditional rule of thumb for SME cash reserves is three to six months of operating expenses. The rule is too generic to be useful and has shifted with the 2026 environment for three reasons.
Interest rates have changed. With the RBA cash rate at 4.10%, the opportunity cost of idle cash is real but modest. Business savings accounts and term deposits are now paying meaningful returns, which makes carrying a slightly larger buffer less penalising than it was when rates were near zero in 2020-22.
Bank lending appetite for SMEs has tightened. Most Australian banks now stress-test SME loan applications against a 30% revenue decline scenario. Businesses without a clear cash reserve face higher rejection rates and worse terms when they need credit, which means relying on a facility as a substitute for cash is less reliable than it used to be.
Payday Super starts 1 July 2026. Until now, businesses have effectively held up to three months of super contributions as working capital between quarterly payments. From 1 July 2026, super must be paid within 7 business days of payday. The float disappears. For a business with a $1.5M payroll, that is roughly $22,500 in working capital that needs to be replaced from cash reserves or other sources within the first month of the new regime. The ATO has detailed guidance on the changes at ato.gov.au/businesses-and-organisations/super-for-employers/payday-super.
The right cash reserve is a function of five inputs, not a flat percentage of revenue.
The total of all fixed and semi-fixed costs the business has to pay every month regardless of revenue. Wages and on-costs, rent, software, insurance, finance leases, key contractors. This is the floor below which the business cannot operate. For a typical $3M revenue services business, this is usually $180,000 to $230,000 per month.
How much can revenue drop in a single month, based on the worst three months in the past two years. A business that has never seen revenue drop more than 10% has different reserve needs than one that routinely sees 30% swings. The data is in your accounting software. Pull a 24-month revenue trend, find the worst single month versus the average, and use that percentage as your downside scenario.
If your top customer is more than 25% of revenue, the loss of that customer is a credible scenario. The reserve needs to cover the recovery period, which for most B2B businesses is 6-12 months of replacement sales effort. For businesses with concentration above 40%, the reserve needs to be substantially higher. Our client concentration risk calculator puts this in numbers.
Highly seasonal businesses (retail, hospitality, tourism, trades) need to fund the trough from the peak. The reserve covers the gap between the lowest cash month and the next reliable inflow. For a Christmas-concentrated retailer, this is typically the gap between mid-January (when cash hits its lowest) and the next BAS refund or major selling period.
Businesses with a committed and undrawn overdraft or working capital facility can hold a smaller cash reserve, because they have a second source of liquidity. Businesses without committed facilities, or with facilities that could be reviewed away in a downturn, need to hold more in cash.
Working through the inputs, the typical reserve targets by profile are as follows.
Stable B2B services business, low concentration, low seasonality, with credit facility. 1.5 to 2.5 months of operating expenses. The downside scenarios are small and the credit facility provides a backstop.
Stable B2B services business, low concentration, no credit facility. 2.5 to 4 months. The cash is doing the job the credit facility would otherwise do.
Growth-stage business, ramping payroll, no committed facility. 3 to 5 months. Growth absorbs cash through working capital expansion (more debtors, more inventory, more staff before the revenue arrives), so the reserve cushions the funding gap.
High customer concentration (top customer 30%+). 5 to 8 months. The reserve needs to cover the loss of the largest customer plus the time to rebuild revenue.
Highly seasonal business (retail, hospitality, tourism, outdoor trades). Cover the full peak-to-trough gap plus 1 month of contingency. For a Sydney retailer with 50% of revenue in November-December, this is often 4-6 months of operating costs held in November to fund January-March.
Cyclical business (construction, capital equipment, large-project services). 6-12 months. Both the revenue cycle and the working capital cycle are long, and a downturn can leave the business funding a large WIP base for an extended period.
Holding the reserve correctly matters almost as much as having it.
Operating account. Wrong place. Earns nothing, blends with operating cash, gets spent unintentionally.
High-interest business savings account (the primary holding). Most major Australian banks now pay competitive rates on business savings accounts, currently in the 3.5-4.5% range. The reserve sits separately from the operating account, earns interest, and is accessible within 1-2 business days.
Term deposits, laddered for partial liquidity. For the portion of the reserve unlikely to be needed in the next 90 days, term deposits at 60-180 days currently pay 4-5%. Laddering means staggering maturity dates so a portion is always coming due. Useful for the larger end of the reserve where some yield pickup is meaningful.
Offset against business loan. Often the highest after-tax return, especially for businesses with property or equipment loans at rates above the RBA cash rate. Holding $200k offset against a 7.5% commercial loan saves roughly $15k a year, which compares favourably to a 4% savings account.
This is general information only. Where to hold the reserve depends on your specific tax position, business structure, and existing facilities. Speak to your tax agent for specific advice.
The temptation is to slash spending and rebuild the buffer in 90 days. For most businesses this is the wrong move because it sacrifices growth without solving the underlying issue.
The better approach is a 12-month plan to build to the target.
Calculate the gap. If the reserve is at 1 month and the target is 3 months, the gap is 2 months of operating costs.
Divide it across 12 months. For a business with $200k/month operating costs, the gap is $400k, requiring $33k/month of additional cash retention.
Find the $33k from three sources combined, not just one. A typical mix is 30% from cost optimisation (Bucket 1 cuts that should have happened anyway), 40% from working capital improvements (debtor days, supplier terms, inventory turns), and 30% from margin/pricing improvements over the year.
Avoid the temptation to load the buffer build entirely onto cost cutting. The owners who do this typically cut into customer-facing capacity and damage the revenue trajectory.
If the cash reserve is materially above the target (more than 2x), the question is what is stopping the deployment of the surplus. Usually it is one of three things.
Recent cash crisis. The owner has been through a tight period and is uncomfortable spending the buffer. Reasonable, but the cost compounds. A reserve sitting 6 months above target on a $3M revenue business represents roughly $80-100k a year in opportunity cost.
No clear deployment opportunities. The business does not have a pipeline of growth investments to deploy capital into. This is a strategy problem, not a cash problem.
Tax considerations. Some owners hold extra cash because of future tax planning, transition planning, or expected lumpy expenditure. This is legitimate, but the cash should be earmarked rather than sitting in a general operating account.
For the deployment question, our fractional CFO ROI calculator and our guide on setting your first financial strategy walk through the framework for capital allocation decisions.
This deserves a section on its own because most owners have not modelled it yet.
Until 30 June 2026, super is paid quarterly. A business running monthly payroll holds two to three months of super contributions as working capital between payment dates. For a $1.5M annual payroll, super at 12% is $180,000 a year, which means roughly $22,500-$45,000 sits in the operating account at any time as accrued super not yet paid.
From 1 July 2026, super is paid within 7 business days of payday. The float disappears. The cash that was effectively interest-free working capital now needs to be paid out within a fortnight of being earned.
Most businesses will absorb this without crisis, but the operating cash position will be permanently lower by 1-2 weeks of super. The cash reserve target should be increased accordingly, by approximately the value of the lost float.
For a stable B2B services business with $3M revenue, $200k/month operating costs, no major customer concentration, modest seasonality, and a $250k undrawn overdraft facility:
Target months: 2.5 (low end of range, given the credit facility backstop)
Target reserve: $200k × 2.5 = $500k
Plus Payday Super adjustment: ~$15k for one month of super float
Final target: ~$515k
Held: $200k as the working operating buffer in the main account, $250k in a high-interest business savings account, $65k offset against an existing equipment loan.
For a seasonal Sydney retailer with $4M revenue, $250k average monthly operating costs, 55% of revenue in November-December, and the worst cash month in February:
Target: cover February-April operating costs from peak-period earnings, with 1 month contingency.
Target reserve at end of December: $250k × 4 = $1M, plus Payday Super adjustment.
Held: heavy weighting to high-interest savings during November-December, drawing down through Q1.
Is 3 months of operating expenses still the right rule of thumb?
It is a starting point, not an answer. For stable B2B services businesses with credit facilities, the actual target is usually lower. For seasonal, concentrated, or cyclical businesses, the target is usually higher. The 5-input framework gives a more accurate target than the flat percentage.
Where should I hold cash reserves to maximise return without losing access?
Most businesses use a combination: a high-interest business savings account for the working portion of the reserve, term deposits or offset accounts for the longer-dated portion. The right mix depends on access requirements, tax structure, and existing loan rates. This is general information only; specific advice should come from your tax agent or financial adviser.
Should I draw down my reserve to invest in growth?
Not below the target. The reserve exists to absorb shocks, not to fund growth. If you have surplus above the target, that capital can be deployed. Drawing the reserve below target to fund growth is one of the most common ways profitable businesses fail.
Does my reserve target change as the business grows?
Yes. The reserve scales with operating costs, not revenue. As you add staff, rent, or fixed costs, the reserve target increases proportionally. Most businesses recalculate the target annually as part of their budget cycle.
Are tax obligations part of the cash reserve?
No. Tax obligations (PAYG, GST, super, payroll tax, income tax) are committed cash flows and should be tracked separately, often in a dedicated tax savings account. The cash reserve sits over and above these committed amounts. Mixing them creates the illusion of a larger reserve than actually exists.
How does Payday Super specifically affect my reserve target?
It removes the quarterly super float that many businesses have used as working capital. From 1 July 2026, super must be paid within 7 business days of payday. For a typical SME, this means an additional 1-2 weeks of super contributions need to be funded from cash rather than from natural payment timing. The reserve target should be increased by approximately the value of one super cycle.
Should I hold reserves in personal savings to access if needed?
No. Personal savings should not be a substitute for business cash reserves. Mixing personal and business cash creates tax complexity, blurs the loan-vs-equity distinction in your books, and rarely ends well. The reserve should sit in a clearly identified business account.
What happens if interest rates fall significantly?
If the RBA cash rate falls below 3%, the opportunity cost of holding cash also falls, and the case for slightly higher reserves strengthens. If rates rise above 5%, the case for tighter reserves and more aggressive deployment of surplus capital strengthens. The framework adjusts naturally with the rate environment.
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We review and check this guide periodically. At the time of writing (April 2026), all information was current. Scale Suite is a registered BAS Agent, not a licensed tax advisor or financial advisor. This content is general information only and does not constitute professional tax, financial, or legal advice. Some details may change over time.
Scale Suite is a Sydney-based provider of outsourced finance and HR services for Australian SMEs. We deliver bookkeeping, financial reporting, payroll processing, fractional CFO support, recruitment, employee onboarding, people and culture support, and fractional HR oversight, all as a fully embedded team that works inside your business.
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