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How a limit is used

Costs arrive weekly. Revenue arrives when it arrives.

A business paid in irregular blocks against steady costs is the natural user of a revolving limit, and it is also the one most likely to lose track of whether the facility is still revolving.

Last reviewed 8 September 2026

Indicative interest cost

Weekly

Disclaimer

$135/week

$583 /month $7,000 a year while drawn
$120,000
$5,000 $500,000
$50,000
Nothing drawn Fully drawn
14.00% p.a.
8% (secured) 30% (unsecured)

Indicative only. Not a quote or offer of credit. Actual rates, fees, and repayments depend on the business profile and the lender's decision.

The short version

Five lines about the sawtooth.

  • The shape should be a sawtooth. Drawing up over the weeks between receipts, dropping sharply when one lands, and repeating.
  • The peaks matter less than the troughs. A rising peak is ordinarily growth. A rising trough is permanent debt forming underneath the pattern.
  • Size it on the longest gap, not the average. The relevant number is the longest period the business has gone between receipts, plus a margin.
  • Repay the day the money lands. Interest accrues daily, so cash sitting in the account rather than reducing the balance is costing money for no reason.
  • Indicative only. Every figure here is illustrative and no facility is offered here. Terms come from a lender after assessment.

The pattern

What lumpy income does to a facility.

Wages, rent, subscriptions and everything else leave the account on a steady rhythm. Revenue arrives when a project completes, a milestone is certified, a commission settles or a contract pays, which might be every three weeks or every eleven depending on the business.

Between receipts the drawn balance climbs at roughly the rate of the fixed cost base. When a receipt lands it drops, ideally back to something close to zero, and then the climb starts again. Plotted across a year, that is a sawtooth, and the regularity of it is what tells a business the facility is doing its job.

The pattern is entirely normal and it is not a sign of difficulty. What matters is not the height of the teeth but where their bases sit, because that is the number that separates a facility smoothing a month from one funding a shortfall.

Between receipts

The balance climbs

On a receipt

It drops sharply

Healthy

It reaches the same floor

Unhealthy

The floor rises

Worked example

A consultancy across eight months.

A consultancy has a fixed cost base of about $14,000 a week and bills on completion, receiving between $60,000 and $180,000 at intervals of four to nine weeks. It holds a $120,000 limit at an indicative 14%.

In a good stretch the balance climbs to about $85,000 over six weeks, a $140,000 receipt lands, and the facility clears entirely with cash left over. In a slower stretch it climbs to $110,000 over eight weeks, a $70,000 receipt lands, and the balance only falls to $40,000 before the next climb begins.

The second stretch is where attention is required. The peak was close to the limit, which is uncomfortable, and the trough at $40,000 means the following cycle starts from a base rather than from zero. One such stretch is a timing event. Three in a row is a pattern, and the difference is visible immediately if the troughs are being recorded.

Illustrative figures

Weekly fixed cost
~$14,000
Limit
$120,000
Good stretch peak
~$85,000
Good stretch trough
$0
Slow stretch peak
~$110,000
Slow stretch trough
~$40,000

Illustrative on stated assumptions and rounded. Not a projection for any particular business.

The number that matters

Record the trough after every receipt, not the peak before it.

The peak tells a business how large the limit needs to be. The trough tells it whether the business is actually covering its costs. A trough that returns to a similar level after each receipt means the facility is smoothing timing and nothing more. A trough that steps up each cycle means the receipts are not covering the period they funded, and that is a margin or a pricing conversation rather than a limit conversation. It takes one line in a spreadsheet after each receipt to know which is happening.

Sizing and running it

Three things that keep the pattern working.

  1. 01

    Size on the longest gap the business has actually had

    Not the average interval between receipts but the longest, taken from the bank statements rather than from memory, multiplied by the weekly cost base and with a margin on top. A limit sized on the average will be short in exactly the stretch it was needed for.

  2. 02

    Repay the day the receipt clears

    Interest accrues daily on the balance, so a $100,000 receipt sitting in the account for a week before it is applied costs real money for no purpose. Making the transfer part of the same routine as banking the receipt removes the decision entirely.

  3. 03

    Track billing dates as well as invoice dates

    On milestone work the date the milestone is certified matters more than the date the invoice is issued, because certification is what starts the payment clock. A milestone certified late is a facility drawn longer, and it is usually visible weeks in advance.

Instrument choice

Why a schedule fights this pattern.

A scheduled facility asks for the same amount every week regardless of what has arrived, which is the opposite of what this business needs.

FeatureRevolving limitTerm loanInvoice finance
Payment required in a quiet weekNoneThe full instalmentNone
Cost in a busy periodLittle, if clearedThe same as alwaysLittle, if repaid
Available for the next gapYesNoYes
Depends on invoices existingNoNoYes
Suits milestone billingWellPoorlyOnly once certified

Invoice finance is a strong alternative where the work is invoiced on completion and the wait is for payment. It does not help during the period before a milestone is certified, which on project work is frequently the longest part of the gap.

The pattern

What a revolving limit does well here, and what it does not.

What it does well

  • Asks for nothing in the weeks between receipts
  • Charges only for the days the balance is actually outstanding
  • Absorbs a receipt arriving three weeks late without any renegotiation
  • Clears completely when a large receipt lands, restoring full headroom
  • Removes the pressure to chase a client harder than the relationship can take

What it does not

  • Force the balance down, which is how a trough starts to rise
  • Distinguish a slow month from an unprofitable one
  • Grow when the business does, without a review
  • Survive a review where the pattern has hardened
  • Fix a pricing problem that the receipts are quietly revealing

When it goes wrong

Three ways the sawtooth flattens.

A receipt is delayed past the next cycle

The balance climbs into a second period without the drop, reaching the limit at a point where nothing can be done quickly.

What happens:An excess or a dishonoured payment on a business that is entirely solvent, caused by one clientโ€™s payment run.

The troughs step upward

Each receipt clears a little less than the last, so every cycle begins from a higher base and the facility never returns to zero.

What happens:Permanent debt forming underneath a pattern that still looks like normal fluctuation on a monthly balance.

The limit is reached in a good period

Growth means larger projects, longer certification periods and a bigger cost base, so the same pattern needs a larger limit than it did last year.

What happens:A constraint arriving during success rather than difficulty, which is the version that is commonly not planned for.

The second is the one to watch for and the easiest to miss, because every individual month looks like the fluctuation the facility exists to handle. The trough record is the only place it shows early.

The honest test

What a rising trough is actually saying.

A business whose receipts consistently clear the period they funded has a timing problem, and a revolving limit solves timing problems well. A business whose receipts consistently clear a little less than the period cost has a margin problem, and the facility is absorbing it quietly rather than solving it.

The distinction is worth being blunt about, because a limit is exactly the instrument that allows the second situation to persist. There is no schedule to miss and no lender asking questions until a review, so a slow deterioration can run for two years before anything forces the conversation.

The test is a job-level calculation rather than a monthly one. Full cost of delivering a project, including the funding cost of the weeks between spending and being paid, against what the project earned. A business that can answer that per project knows which of the two situations it is in, and one that cannot is relying on the facility to tell it eventually.

The trade

What a limit does for lumpy income, and what it does not.

What it does

  • Asks for nothing in the weeks between receipts
  • Charges only for the days a balance is actually outstanding
  • Absorbs a receipt arriving three weeks late without renegotiation
  • Clears completely when a large receipt lands
  • Removes the pressure to chase a client harder than the relationship allows

What it does not

  • Force the balance down between receipts
  • Distinguish a slow month from an unprofitable one
  • Grow when the projects grow, without a review
  • Survive a review where the pattern has hardened
  • Fix pricing that the receipts are quietly revealing

Structuring the work

Billing changes that shorten the gap more than a facility does.

A deposit at engagement moves cash to the start of the work rather than the end of it, and on project work it is ordinary practice rather than an unusual request. On a three-month engagement it can remove a third of the funding requirement outright.

Progress billing does the same across the middle. Invoicing at agreed points rather than at completion converts one long gap into several short ones, and clients who baulk at a deposit frequently accept staged invoicing without argument because it matches how they think about the work.

Both are commercial conversations rather than financial ones, and both are worth more than a rate negotiation on a facility. A business that shortens its own billing cycle by three weeks needs less limit permanently, and the change costs nothing to make.

The cost of the gap

What smoothing the month costs.

A revolving facility charges on what is drawn, so this shows the interest cost of an average drawn balance across the year rather than a repayment. Indicative only, and not a quote or offer of credit.

Indicative interest cost

Weekly

Disclaimer

$135/week

$583 /month $7,000 a year while drawn
$120,000
$5,000 $500,000
$50,000
Nothing drawn Fully drawn
14.00% p.a.
8% (secured) 30% (unsecured)

Indicative only. Not a quote or offer of credit. Actual rates, fees, and repayments depend on the business profile and the lender's decision.

References

Sources

FAQ

Managing irregular income, questions answered

Why does a revolving limit suit lumpy income?

Because it asks for nothing in the weeks between receipts and charges only for the days a balance is outstanding. A scheduled facility asks for the same instalment regardless of what has arrived, which fights the pattern rather than absorbing it.

How should the limit be sized?

On the longest gap between receipts the business has actually had, taken from the bank statements, multiplied by the weekly cost base with a margin on top. A limit sized on the average interval will be short in the stretch it was needed for.

What is the sawtooth?

The shape the drawn balance makes over a year: climbing between receipts, dropping when one lands, and repeating. A regular sawtooth with consistent troughs is a facility doing its job.

Why do the troughs matter more than the peaks?

A rising peak is ordinarily growth, meaning larger projects and a bigger cost base. A rising trough means each receipt is clearing less than the period it funded, which is permanent debt forming underneath the pattern.

When should a receipt be applied to the facility?

The day it clears. Interest accrues daily, so a large receipt sitting in the account for a week costs real money for no benefit, and making the transfer part of the banking routine removes the decision.

Is invoice finance a better fit?

It can be where the work is invoiced on completion and the wait is purely for payment. It does not help during the period before a milestone is certified, which on project work is frequently the longer part of the gap.

What happens if a receipt is delayed past the next cycle?

The balance climbs into a second period without the drop and can reach the limit. Knowing the longest historical gap and sizing with a margin is what keeps that from becoming an excess on an otherwise solvent business.

Does growth make this harder?

Frequently. Larger projects mean longer certification periods and a bigger cost base between receipts, so a limit that fitted last year can constrain the business during a successful period rather than a difficult one.

How do I tell a slow month from a margin problem?

By costing a project fully, including the funding cost of the weeks between spending and being paid, and setting that against what the project earned. Monthly totals will not separate the two; job-level figures will.

Should the facility return to zero?

After a substantial receipt, ideally yes or close to it. A facility that consistently clears is smoothing timing. One that never quite clears is carrying a balance the receipts are not covering.

Is a term loan ever better here?

Rarely, because it requires the same payment in a week where nothing has arrived and charges interest on the whole amount throughout. The one case is a genuine one-off need with a defined end, which is a different thing from this pattern.

Is this page financial advice?

No. It describes a usage pattern in general terms. This site is not a lender, a broker or a registered financial adviser, and what suits a particular business depends on facts a website cannot see.

Disclaimer

Indicative content only. Not personalised financial advice.

A revolving facility is a standing commitment serviced out of the same operating cash flow as everything else, and the interest and fees recur for as long as it is held. Modelling the weekly cost against the trading position before committing is what this site is built for. Borrowing at a level that stays comfortable through a quiet quarter, rather than only through a strong one, is widely regarded as the safer frame.

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A calculator and information tool. Not a lender, not a broker, not a registered financial adviser. Nothing here is personalised financial advice.

What the figures show

Modelled estimates based on the inputs shown. Not a quote. Not an offer of credit. Not a guarantee of approval, rate or fees.

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Final rates, fees, and approval are set by the lender after a CCCFA-appropriate assessment of the applicant's circumstances and credit decision.

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Tax, GST, and accountant framing

Tax-treatment statements (GST claim timing, interest deductibility, depreciation rates) are general in nature and subject to the accountant's confirmation on the specific business position. For material amounts, professional advice from a registered financial adviser or chartered accountant is widely regarded as the safer frame.

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Last reviewed 8 September 2026.

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