How much buffer should a builder keep outside working capital?

Many self‑employed builders are safer with 6–12 months of combined household and business expenses held in separate buffers, not tied up in overdrafts or operating accounts. This gives you time to manage delays, bad debts or cost overruns without immediately missing tax, wages or home‑loan payments. The higher your contract concentration and leverage, the closer to 12 months you should lean.

Article

Construction Cashflow 101: Progress Claims, Retentions And Funding Gaps

Written and reviewed by James Chee, CPA · Last reviewed 29 October 2026

A plain‑English guide to progress claims, retentions and cashflow gaps in Australian construction, plus funding options tradies and builders can act on this week.

Published 29 Oct 2026Updated 29 Oct 20268 min read

Key Takeaway

Construction working capital finance helps Australian builders and tradies bridge cashflow gaps created by progress claims, retentions and delayed payments, which can easily run 30–90 days. By mapping weekly cash in and out on each project, then stress‑testing for 20–30% cost overruns and slow payers, owners can size an overdraft, invoice finance or project facility safely. The key actionable insight is to match funding terms and security to job duration and risk, rather than relying on personal home-loan redraw or offsets.

Watch the short answer

Subcontractors relying on progress payments

If you’re juggling slow progress pays on site, this video walks through practical cash flow options that build on what you’ve just read.

Talk to a broker about your situation

Read the transcript

If you are a subcontractor relying on progress payments from a head contractor who regularly stretches your terms out to 60 days, you are funding their business at the expense of your own. You shouldn't have to freeze your growth because someone else is slow to pay. We build flexible commercial invoice lines that release up to 85% of your values in 24 hours. DM me 'UNCLOG' to claim your cash flow back.

General information only, not personal advice. Your situation is assessed before any recommendation.

Construction Cashflow 101: Progress Claims, Retentions And Funding Gaps

This topic is covered in full on Local Knowledge Finance

A plain‑English guide to progress claims, retentions and cashflow gaps in Australian construction, plus funding options tradies and builders can act on this week.

Read the full guide on ding.financial

Construction working capital finance helps builders and tradies cover wages, suppliers and subcontractors while waiting to be paid on progress claims and retentions, usually over 30–90 days. The aim is to fund that gap with purpose‑built business facilities, not your home loan redraw or personal offset, so trading risk doesn’t land on the family home.

If you’re running jobs now, your priority this week is simple: map your actual cash gap per project, then decide whether an overdraft, invoice finance or specialist progress‑claim facility is the best fit.

Construction manager reviewing progress claim and cashflow chart. Mapping progress claims against costs shows the real funding gap on each job.

1. How construction working capital really behaves

1.1 The construction cashflow pattern

Compared with many industries, construction has three extra stress points:

Front‑loaded costs – mobilisation, deposits to suppliers, insurances and site establishment before the first claim.
Progress claims – typically monthly, often certified by a superintendent or client before payment.
Retentions – 2–10% of each claim withheld until practical completion, then end of defect period.

That means you can be profitable on paper but cash‑poor in reality. As outlined in /insights/industry-specific-working-capital-patterns-risks, project‑based businesses like builders must size working capital around the worst month, not the average year.

1.2 Typical timing in Australia

While every contract differs, a common pattern is:

Payment terms: 30 days from claim approval, but 45–60 days in practice.
Retentions: 5% total (2.5% until practical completion, 2.5% until end of defects liability period, say 12 months).
Variations: often disputed or delayed.

Layer in the APRA 3% home‑loan serviceability buffer and rising input costs (the ABS Producer Price Index for construction is still running above general inflation), and personal and business resilience become tightly linked.

2. Progress claims, retentions and the real cash gap

2.1 Worked example: a $1.2m contract

Assume a builder wins a $1.2m (ex‑GST) project, expected to run 9 months, with:

5% retention (2.5% at practical completion, 2.5% at 12 months)
Monthly claims based on work done
30‑day terms, but paid on average 45 days after claim

Rough cash profile (simplified):

Month	Cumulative costs paid (A$)	Cumulative claims approved (A$)	Retentions held (A$)	Cash position vs costs*
1	120,000	100,000	5,000	-25,000
3	400,000	350,000	17,500	-67,500
6	800,000	750,000	37,500	-87,500
9	1,150,000	1,140,000	57,000	+47,000
21**	1,200,000	1,200,000	0	+0

*Assumes claims are eventually paid in full; ignores overheads. **End of 12‑month defects period.

Even with no blowouts, this builder needs capacity to fund at least $90k–$100k of gap on this one job, plus overheads and any other projects. If material prices jump 15% mid‑project, that gap can widen fast.

3. Mapping your construction cashflow gaps

3.1 Three steps to quantify the funding need Before you talk to any lender or broker, do this on a single page per project: 1. Plot costs by week or month – wages, super, PAYG, subcontractors, materials, insurances, plant hire. 2. Plot income – when you can realistically claim, when clients usually approve, when they actually pay. 3. Calculate the running gap – cumulative costs minus cash in. Repeat across all active jobs and overlay overheads (office rent, admin wages, vehicles, tax instalments). The largest combined negative number is…

Premium insight

The strategy continues below

You've seen the problem and the groundwork — now unlock the exact steps our CPA and Registered Tax Agent-led brokers use, including 4 more sections. Enter your email for instant, free full access.

Free access. No spam — unsubscribe anytime. Your details stay confidential.

Frequently asked questions

Progress claims delay cash inflows because you only bill after work is completed and then wait for approval and payment, often 30–60 days. During that period you still have to pay wages, subcontractors and suppliers. That timing gap between cash out and cash in is your working capital need, and it usually grows with project size and duration.

Retention is a portion of each claim, commonly 5–10%, that the client withholds as security against defects or incomplete work. You may only receive it at practical completion and after a defects liability period. It ties up your cash and margin for months or years, so if you don’t plan for it, you can appear profitable on paper while running dangerously low on cash.

Invoice finance can suit tradies who regularly bill commercial, industrial or government clients and face slow payment terms. It’s less useful for small, one‑off domestic jobs because the administration and fees can outweigh the benefits. The key question is whether your debtor book is large, regular and reliable enough to justify the structure and cost versus a simple overdraft.

Securing working capital against your home generally lowers interest costs but increases the risk that a bad project could ultimately cost you the property. Unsecured facilities are more expensive but limit the damage to the business if things go wrong. The right mix depends on your gearing, contract risk and how much volatility your household can realistically absorb.

Talk to a broker who is a CPA and Registered Tax Agent

Free consultation, plain-English advice tailored to your situation.

All insights