What Is a 3-Way Forecast? A Plain-English Guide for SMEs

According to ASIC's insolvency data, 14,722 Australian companies entered external administration in 2024-25, and the pace has stayed near record levels since. A large share of them were profitable on paper. They failed on timing: the BAS, the wages and the supplier bill all landed before the customer money did.

A 3-way forecast is the tool built for exactly that problem. This guide explains what it is, how the three statements connect, how to build one step by step, and walks through a worked example where a $25,000 profit month drains $12,000 of cash. It is written for owners who want to understand the model, not just buy one. We look at numbers this way with every client at 42 Advisory, because it is how we run our own firm.

What Is a 3-Way Forecast?

Most small businesses run on one report: the profit and loss. It answers "did we make money?" but stays silent on "can we pay the BAS in April?" and "what will the bank balance be in November?". Those answers live in the interaction between all three statements, which is what the 3-way model captures. The ATO's own cash flow guidance pushes businesses toward regular forward projections for the same reason: obligations are predictable, and running out of cash for a predictable bill is an avoidable failure.

We describe it to clients as looking through the windscreen instead of the rear-view mirror. Your accounting file tells you where you have been. The 3-way forecast tells you what the road ahead does to your bank balance.

How Do the Three Statements Link Together?

The balance sheet is the part most owners skip, and it is where the surprises live. Four items routinely move cash without ever appearing as an expense: GST collected and remitted through the BAS, loan principal repayments, inventory bought but not yet sold, and customer invoices raised but not yet paid. Each one sits on the balance sheet, not the profit and loss. A forecast that ignores them is just a hopeful budget.

This is also why the model is industry-specific. A medical practice forecasts consulting sessions, billings and wages. An e-commerce brand lives and dies on inventory cycles and ad spend. A gym or studio models memberships against fixed lease costs. The statements link the same way in every case; the drivers differ.

Why Can a Profitable Business Still Run Out of Cash?

Worked example: a $25,000 profit month that drains $12,000 of cash

A Melbourne homewares e-commerce brand has its best November yet. The profit and loss shows revenue of $120,000, cost of goods sold of $54,000 and operating costs of $41,000: a profit of $25,000. The owner expects the bank balance to rise. It falls by $12,000. Here is the cash side of the same month:

• Cash in: $120,000 (customers pay at checkout).
• Cash out: operating costs $41,000, inventory purchases $68,000 (the Christmas stock build), September-quarter BAS $19,000, loan principal $4,000. Total $132,000.
• Net cash movement: negative $12,000, in a month that made $25,000 of profit.

The $37,000 gap reconciles exactly: $14,000 of stock bought but not yet sold (purchases of $68,000 against $54,000 expensed), $19,000 of GST that never touches the profit and loss, and $4,000 of loan principal. None of this is a problem if it is forecast; the Christmas stock will sell and the cash comes back in January. It becomes a crisis only when it arrives unannounced in the same month as wages. Importers face an added layer, because freight and duty sit in stock until sold, which our landed cost guide covers in detail.

How Do You Build a 3-Way Forecast?

The build follows five steps:

• Step 1: Start from clean actuals. The forecast inherits the quality of the accounting file behind it. Reconciled bank feeds and a tidy ledger, the core of good bookkeeping, come first.
• Step 2: Set revenue drivers, not a growth percentage. Sessions times fee, orders times average order value, members times monthly rate. Drivers make assumptions arguable; "plus 10%" makes them invisible.
• Step 3: Map costs and payroll with their real timing. Wages weekly or fortnightly, super with every pay run under Payday Super, rent monthly, insurance annually. The calendar matters as much as the amount.
• Step 4: Add the balance sheet timing assumptions. Debtor days, creditor terms, inventory ordering cycles, the quarterly BAS cycle, PAYG instalments and loan schedules. This step is what makes it a 3-way model rather than a budget.
• Step 5: Test scenarios. What happens if sales fall 15%, a key customer pays 30 days late, or you bring the second hire forward? The point of the model is to answer these before reality does.

Tools matter less than structure. The Australian Government's budgeting templates and cash flow planning guide are a genuine starting point for a simple business. Once there are multiple revenue streams, inventory or debt, a properly linked model built by an adviser earns its keep, because a spreadsheet where the three statements do not reconcile gives false comfort. That build-and-maintain work is what our business advisory and forecasting service does, with the model wired to the live Xero file.

Why Do Banks Ask for a 3-Way Forecast?

The Reserve Bank's analysis of small business finance makes the pattern plain: smaller businesses find credit hardest to access where lenders perceive uncertainty in their financial information, and transparency weighs heavily in credit decisions, particularly for businesses without long trading histories. A credible forecast reduces perceived risk, and that is often the difference between a decline and an approval, or between a punitive rate and a commercial one.

One example from our own client base: a new GP practice, trading for only six months, needed finance when its leased premises unexpectedly went to market. A linked 3-way model and three-year projection supported a $2 million facility. The mechanics of that engagement, and how we run forecasting alongside our commercial finance partners, are on our advisory and forecasting page.

How Often Should a 3-Way Forecast Be Updated?

The monthly pass is short: replace forecast with actuals, note the variances, and ask why. Sales drivers, wage changes, supplier cost movements and interest rates drift constantly, and the variances are where the useful conversations start. This rhythm also feeds directly into tax: a live forecast is what lets you vary PAYG instalments with confidence, time deductions, and plan distributions before 30 June rather than after, which is the substance of our tax planning work. The dates worth planning around are in our ATO due dates guide.

What Are the Most Common 3-Way Forecasting Mistakes?

The industries where timing bites hardest illustrate the point. Construction businesses fail on retention money, progress claim timing and quarterly BAS far more often than on margin, which is why we wrote a separate guide to cash flow management for construction. Startups make a different version of the same mistake: modelling the raise but not the runway between raises, a gap our startup advisory work exists to close. In every case the fix is the same: put the timing on the balance sheet and let the cash flow fall out honestly.

Key Takeaways

• A 3-way forecast links the profit and loss, balance sheet and cash flow so every decision shows its cash consequence before you commit.
• Profit is not cash. GST, loan principal, inventory and debtor timing all move the bank balance without touching profit.
• Build from reconciled actuals, use drivers rather than growth percentages, and put the timing assumptions on the balance sheet.
• Update monthly and keep a rolling 12-month horizon; extend to three years when finance is on the agenda.
• If the numbers matter to a lender, the ATO or a hiring decision this year, get the model built properly once, then keep it alive.

Frequently Asked Questions