Rate Rise Cash Flow Check: How Much Buffer Does Your Business Need Now?

A rate rise cash flow check adds up every facility your business holds and applies the rate change to the variable ones. It then compares the new total repayment with your monthly operating surplus. It gives you three numbers: the extra monthly cost, the price rise that would absorb it, and the cash buffer worth holding.

On 29 September 2026 the Reserve Bank of Australia's Monetary Policy Board raised the cash rate target by 25 basis points to 4.60%. A basis point is one hundredth of a percentage point, so 25 basis points is 0.25 percentage points.

Why does a rate rise hit small business cash flow harder than the repayment table suggests?

The repayment is only the first effect. The RBA's 29 September 2026 statement noted that firms are experiencing cost pressures while business debt growth is strong; higher repayments land on top of dearer fuel, freight and inputs. Customers facing the same squeeze may spend less, so revenue can soften as costs rise. A cash flow check measures all three together.

The same RBA statement said higher fuel prices have been partially passed through to other goods and services. The people who buy from you were surveyed too.

AAP reported on 6 October 2026 that the Westpac-Melbourne Institute consumer sentiment index fell to 80.4 in October. The same AAP report said respondents surveyed after the 29 September decision recorded 67.2, the lowest since the late 1990s. Those are survey readings, not a forecast of spending.

121 Brokers, an Australian business finance broker, arranges lines of credit, overdrafts and term loans across a panel of lenders; lenders calculate serviceability their own way and make their own decisions. This is the whole-business view; whether to wait for rate cuts on equipment is its own guide.

How much extra will the rate rise cost across all my facilities?

Add the change on each variable facility and ignore the fixed ones. The example pairs a $200,000 variable term loan at an illustrative 9.00% over 48 months with a $50,000 drawn line of credit at 11.00% interest-only. Together they cost $34.19 a month more for 25 basis points, and $137.17 for 100. The calculator below handles up to three facilities.

Interest-only means the balance does not fall, so the whole drawn amount reprices. All figures in this example are invented illustrations, not quotes; 9.00% and 11.00% are the calculator's illustration rates. The invented business has monthly revenue of $80,000 and operating costs of $62,000 before loan repayments, so an operating surplus of $18,000, with $40,000 cash on hand. Facility 1 is the variable-rate term loan on principal and interest; facility 2 is the drawn line of credit, interest-only.

Surplus after repayments is $12,564.66 now, $12,530.47 after 25 basis points and $12,427.48 after 100, the four 2026 rises together. Three months of repayments is $16,408.60 at 25 points and $16,717.55 at 100; six months is $32,817.20 and $33,435.10. With $40,000 cash on hand the gap is $0 at every target, and surplus stays positive.

Now enter your own facilities, fixed ones included (the calculator leaves fixed facilities unchanged), then try three variations. Cash on hand of $10,000 instead of $40,000 turns the three-month gap at 25 points into $6,408.60 and the six-month gap into $22,817.20.

Quiet-quarter revenue of $66,000 with the 100 point chip turns surplus after repayments to $1,572.52 short each month, a runway of about 25 months of cash at that rate of loss. Facility 1 set to fixed cuts the extra at 25 points to $10.42, the line of credit alone.

The calculator uses average months; a seasonal business should test its quietest quarter, as our guide to off-season cash flow for Byron Bay and Ballina hospitality shows. The same numbers in a table, largest extra first:

Which facility should I review first?

Start with the largest variable balance, where most of the dollars are: $95.51 of the example's $137.17 comes from the term loan. Then any interest-only facility, because its whole balance reprices. Fixed facilities last: a fixed rate holds until its fixed period ends, so note that date, because the facility reprices then at a rate the lender sets. The break-even maths of fixing covers that moment.

How do I run a rate rise cash flow check?

A rate rise cash flow check works through six steps, from listing every facility to comparing your cash with a buffer target. It applies the rate change only to the variable facilities, so fixed ones do not move. You end with the extra monthly cost, the surplus left, the price rise that would cover it and your buffer gap.

1. List every facility. Write down each loan, line of credit, overdraft and equipment contract with its balance, rate, remaining term, whether the rate is fixed or variable, and whether you pay principal and interest or interest-only. In the worked example that is a $200,000 variable term loan and a $50,000 drawn line of credit.
2. Work out this month's total repayment across all facilities. Add up what every facility costs you this month. The example totals $5,435.34: $4,977.01 on the term loan and $458.33 of interest on the line of credit.
3. Apply the rate change to the variable facilities only. Recalculate each variable facility at the higher rate and leave fixed facilities unchanged. At 25 basis points the example rises to $5,469.53, an extra $34.19 a month; at 100 basis points it rises to $5,572.52, an extra $137.17.
4. Subtract the new total from your monthly operating surplus. Operating surplus is revenue less operating costs before loan repayments. The example's $18,000 surplus leaves $12,530.47 after repayments at 25 basis points, and repayment cover of 3.29, down from 3.31.
5. Convert the extra cost into the price rise that would cover it. Divide the extra monthly cost by monthly revenue. In the example $34.19 divided by $80,000 is 0.04%, and $137.17 is 0.17%: the across-the-board price increase that would absorb the rise if sales volume held.
6. Compare cash on hand with a three or six month repayment buffer. Multiply the new monthly total by three and by six and compare each with the cash you hold. The example needs $16,408.60 for three months and $32,817.20 for six, both covered by $40,000 cash. If surplus turns negative, cash on hand divided by the monthly shortfall is your runway in months.

How much cash buffer does a small business need after a rate rise?

There is no universal figure, but a common working range is three to six months of total loan repayments held in cash or an undrawn facility you control. Three months covers a slow quarter; six covers a slow quarter plus a shock. The right number depends on how seasonal revenue is and how fast you can cut costs.

The calculator shows the gap to each target. On the worked example at 25 basis points:

• Three months of repayments: $16,408.60. Covers a slow quarter, not a second shock in the same quarter such as a lost customer or one more rise.
• Six months of repayments: $32,817.20. Covers the quarter plus one more rise or a lost customer, at the cost of more idle cash that could be working capital.

Cash on hand of $40,000 covers both targets in the example; at $10,000 the gaps are $6,408.60 and $22,817.20. A seasonal business should enter its quietest quarter divided by three, because an average month hides the quarter where the shortfall appears. The buffer is sized on total repayments, not on the single-loan arithmetic in what the RBA rate rise adds to one business loan repayment.

What is repayment cover, and how do lenders look at it?

Repayment cover is your operating surplus divided by your total loan repayments. A result of 2.0 means surplus covers repayments twice over; 1.0 means nothing is left. Lenders use their own versions of this test, often called serviceability or debt service coverage, with their own adjustments and buffers. Treat the calculator's figure as a health check, not a lender's verdict.

In the example, cover is 3.31 now, 3.29 after 25 basis points and 3.23 after 100. Drop revenue to a quiet-quarter $66,000 and apply 100 points, and cover falls to 0.72: an operating surplus of $4,000 against repayments of $5,572.52.

A lender's version, often called a debt service coverage ratio (DSCR), may add a buffer to the rate, shade some income and count commitments the calculator does not see. For what those adjustments tend to be, see how much your business can borrow and the borrowing power calculator.

Should I pass the extra cost on to customers or absorb it?

Start with the arithmetic: the extra monthly cost divided by monthly revenue is the across-the-board price rise that would cover it if volume held. Whether volume holds is the real question; AMP economist My Bui said on 6 October 2026 that tightening household budgets limit how far businesses can pass on input price rises.

In the example that is 0.04% at 25 basis points and 0.17% at 100. Whether a move that size is noticed depends on your customers and competitors, not the arithmetic. Five common responses, none a recommendation:

What does the rate rise do to ATO debt on a payment plan?

The ATO's general interest charge is reset every quarter from a market rate plus a fixed uplift. A higher cash rate therefore tends to flow into a higher GIC with a lag. The ATO's GIC is 11.51% p.a. for the October to December 2026 quarter, up from 11.43% in the July to September 2026 quarter.

The rate is set under the Taxation Administration Act 1953. The base rate for a quarter is the RBA's 90-day bank bill average for the month two months before the quarter starts, plus 7 percentage points. For October to December 2026 that month was August 2026, when RBA Statistical Table F1.1 put the average at 4.51%; 4.51 plus 7.00 is the ATO's 11.51%. The figure was therefore set before the 29 September decision and is not a consequence of it.

GIC is an interest charge, not a penalty. Deductibility and the plan-or-loan maths are in our guide to the ATO payment plan against paying it out: the 2026 maths and are not repeated here. Lender appetite for ATO arrears varies and is the lender's decision, and this article does not suggest borrowing to pay tax.

Enter the ATO balance, the plan length and the current quarter's GIC to see the two costs side by side, then take both figures to your accountant.

When does a line of credit help with a rate rise, and when does it just add interest?

An undrawn line of credit helps as a buffer: interest is charged only on what you draw, and it covers a timing gap without a new application. Any fee on the undrawn limit is set by the lender. It adds cost when drawn to cover a permanent shortfall, because interest-only balances are the most rate-sensitive debt you can hold.

The $50,000 drawn line in the example adds $10.42 a month at 25 basis points and $41.67 at 100. That is the smaller dollar change of the two facilities, but the only one where the whole balance reprices. Undrawn, the same limit adds nothing to the stress test and sits behind cash as a second layer of buffer. It is not cash, though: an undrawn limit is the lender's to review or reduce. Use it for gaps you can see the end of.

Which facility fits which gap is covered elsewhere on the site:

• Line of credit, overdraft or term loan for your cash flow gap, which matches the facility to the shape of the gap.
• Line of credit vs overdraft and term loan vs line of credit, which set the pairs side by side.
• How a business line of credit works, which covers the mechanics.

Our line of credit page explains how we arrange one. 121 Brokers can price a buffer facility across a panel before the quiet quarter rather than during it; whether a limit is approved, and at what size, is the lender's decision. Start with a scenario call with your statements and the calculator's numbers; for the application side, see how to get a business loan in Australia.

What economists expect next, and why it is not a promise

Figures in this section are as at 7 October 2026 and are reviewed after each RBA meeting; the next is 2 to 3 November 2026.

On 4 October 2026 the Australian Financial Review's survey of 37 economists found that 16 expected at least one more rise and 21 expected the next move to be a cut. The same AFR survey put the broad view of a first cut at November 2027. For a cash flow plan that means testing both 25 and 100 points and holding a buffer that survives either. These are forecasts, dated, not promises.

The range is wide because the inputs are. The same AFR survey of 4 October 2026 reported core (trimmed mean) inflation at 3.6% against the RBA's 2.5% target, and oil above US$100 a barrel against closer to US$70 before February 2026. It also reported ANZ forecasting a rise to 4.85% in November 2026, Commonwealth Bank and NAB forecasting no change, and markets pricing roughly a one-in-four chance of a November 2026 rise.

The RBA's Monetary Policy Board statement of 29 September 2026 also gave its guidance. It said: "The Board will continue to do what it considers necessary to bring inflation sustainably back to target, including increasing the cash rate target further if needed." A buffer sized to the 100 point chip is the one plan that does not depend on any of these forecasts being right.

General information only, not financial, tax or legal advice. 121 Brokers is a finance broker, not a lender. The revenue, cost, cash and facility figures in the worked example are invented illustrations and the calculator's default rates are illustrations, not quotes. Repayment cover as calculated here is a health check; lenders assess serviceability their own way and make their own decisions, including on ATO arrears. The ATO general interest charge is quoted as published for the quarter named and changes each quarter. Nothing here suggests borrowing to pay a tax debt; discuss any tax debt with your accountant. Forecasts quoted are the dated views of the people and organisations named. Whether any facility is approved, and on what terms, is decided by the lender.

Sources

• Reserve Bank of Australia, Statement by the Monetary Policy Board, 29 September 2026
• Australian Taxation Office, General interest charge rates (October to December 2026 row)
• Reserve Bank of Australia, Statistical Table F1.1, Money Market Interest Rates (90-day bank bill, August 2026)
• Australian Financial Review, Cecile Lefort, quarterly economist survey, 4 October 2026
• Australian Financial Review, Michael Read, consumer confidence after the rate rise, 6 October 2026
• The Guardian / AAP, consumer confidence after the rate rise, 6 October 2026