What is cash flow forecasting?

The reason it matters is that profit and cash are not the same thing and do not arrive at the same time. Your profit-and-loss statement records a sale on the day you invoice it. Your bank account records it on the day the customer pays, which might be 45 days later, or never. Payroll does not wait for either. A business can post its best year on paper and still run out of money in March, and the owners who get caught by that are almost never the ones who were watching the wrong number. They were not watching a forward number at all.

What a cash flow forecast shows that the profit-and-loss statement does not

A profit-and-loss statement is a record of what already happened, measured on an accrual basis. A cash flow forecast is a projection of what is about to happen, measured in actual dollars moving through an actual bank account. The two diverge for entirely ordinary reasons: customers pay late, inventory has to be bought before it is sold, tax is paid in lumps, loan principal never appears as an expense, and growth consumes cash long before it produces any.

That last one catches more good businesses than any other cause. Winning a large new customer usually means paying for labor, materials or headcount weeks before the first invoice is settled. The faster you grow, the wider that gap gets. A forecast makes the gap a number you can plan around instead of a surprise you discover on a Friday afternoon.

What are the two types of cash flow forecasting?

There are two methods, and the difference between them is where the forecast starts. A direct forecast starts from expected receipts and payments. An indirect forecast starts from projected net income and works back to cash. Both are legitimate; they answer different questions over different horizons.

Most businesses that run out of cash were only doing the second one, if they were doing either. The indirect method sits comfortably inside an annual budget and gives no warning about a particular week. Scenario forecasting is sometimes described as a third type; it is better understood as something applied on top of either method, modeling a base case, a downside and an upside so a decision can be tested before it is made.

The 13-week forecast and the 12-month forecast do different jobs

Thirteen weeks is one quarter, and it is the standard short-term horizon for a reason. It is long enough to see a seasonal dip, a slow-paying customer or a tax payment coming, and short enough that the assumptions underneath it are still grounded in real invoices and real commitments rather than guesses. Beyond about a quarter, a direct forecast is mostly estimating.

The 13-week forecast should roll. Each week you drop the week that has passed, add a new week 13, update the opening balance to the real bank balance, and correct the assumptions that turned out wrong. The horizon never shortens, and the discipline of comparing last week's forecast to what actually happened is what makes the next one accurate.

The 12-month forecast is a different instrument. It is built from the budget rather than the ledger, and it answers planning questions: whether the hiring plan is affordable, whether you can fund equipment out of operations or need financing, how much of the year's profit will be tied up in receivables and inventory, and whether the business generates enough cash to service debt.

Running both is not redundant. The 12-month forecast tells you whether the plan works. The 13-week forecast tells you whether you will survive the next quarter of executing it.

How to do cash flow forecasting, step by step

1. Start from the actual bank balance. Not the book balance, not the accounting system's cash figure. The real number, today, across all accounts, less anything already committed.
2. Set the horizon and the interval. Thirteen weeks, in weekly columns, for liquidity. Twelve months, in monthly columns, for planning.
3. Forecast receipts by expected payment date. Go through the accounts receivable ledger customer by customer and place each invoice in the week it will realistically be paid, based on how that customer has actually behaved, not on the terms printed on the invoice. Add expected new sales separately, and be conservative about them.
4. Forecast payments the same way. Payroll and payroll taxes, rent, suppliers, loan principal and interest, insurance, sales and income tax, owner distributions, subscriptions. The items that break forecasts are the irregular ones: quarterly taxes, annual insurance renewals, and anything paid by card that nobody has itemised.
5. Calculate a closing balance for every period. Opening balance plus receipts less payments. That running line is the entire point of the exercise. The lowest point on it is the number that matters.
6. Add a scenario or two. What the line looks like if your largest customer pays 30 days late, or if revenue comes in 20 percent below plan. If the base case is fine but the downside is not, you have found the decision that needs making now rather than later.
7. Compare forecast to actual every single week. Explain every material variance. This is the step almost everyone skips, and it is the step that converts a spreadsheet into a forecast you can trust.

Why forecasts turn out wrong

The failures are consistent, and none of them are complicated.

• Using invoice dates instead of payment dates. If a customer has taken 52 days to pay for the past two years, they are a 52-day customer, whatever the terms say.
• Forecasting revenue instead of collections. A signed contract is not cash. Only the deposit is.
• Leaving out the lumps. Quarterly tax, annual renewals, bonuses and loan principal are the four items most often missing from a forecast that looked fine and then was not.
• Building it once. A forecast that is not updated weekly stops being a forecast within a month and becomes a historical document that happens to be about the future.
• Optimism in the sales line. Every business overestimates new revenue. Forecast the pipeline at a probability you can defend, and let a pleasant surprise be a surprise.

Why the forecast is worth the effort

A forecast is not a reporting exercise. It is what allows an owner to commit to things. Hiring a second crew, taking on an equipment note, offering 60-day terms to win a larger account, funding a slow season without a line of credit: every one of those is a decision that either fits inside your cash position or does not, and the forecast is the only place that question gets answered before the money moves.

It also changes how lenders and investors treat you. A business that can produce a maintained 13-week forecast and explain last quarter's variances is presenting evidence that somebody is managing the money. A business that cannot is asking to be taken on trust. That difference shows up in terms, in covenants and in how quickly a request gets approved.

When to move from a spreadsheet to a managed process

A one-person business with predictable receipts can run a perfectly good forecast in a spreadsheet, maintained on Monday mornings. The point at which that stops working is usually the point at which the forecast starts driving decisions other people have to act on, or the point at which the owner no longer has a free hour on a Monday.

At that stage the work is less about the model than about the rhythm around it, which is what our cash flow management and forecasting service provides: a rolling 13-week forecast maintained weekly, variance analysis against actuals, working capital review, and a monthly session with the owner about what the numbers are actually saying. Consulting is billed at $250 per hour, and ongoing work runs on monthly advisory plans priced to the needs of your business. You can compare that against the alternatives on our page covering what a fractional CFO costs, see the wider set of engagements under CFO services, or book a free strategy call.

Key takeaways

• Cash flow forecasting projects money in and out over a set horizon. It is a different measurement from profit, and the gap between the two is what causes profitable businesses to run short.
• The two types are direct, built from expected receipts and payments and accurate to about 13 weeks, and indirect, built from projected net income and useful over 12 months or more.
• A 13-week rolling forecast manages liquidity. A 12-month forecast tests the plan. Serious businesses run both.
• Forecast receipts by when customers actually pay, not by invoice terms, and include the irregular payments: quarterly tax, annual renewals, bonuses and loan principal.
• Comparing forecast to actual every week is what makes a forecast trustworthy, and it is the step most often skipped.