Your P&L says the business is profitable. The bank balance disagrees. Payroll runs on its own schedule, vendors expect payment on their terms, the equipment loan and the line of credit want their monthly service, and the next tax date is already on the calendar. None of those obligations wait for the profit on the income statement to turn into money you can spend.
This is not a question about whether the business is profitable. Assume the pricing is sound and the jobs earn a real margin. The trouble is timing, together with the movement of cash that never reaches the P&L at all. Profit and cash answer two different questions, and once you separate them, the gap between the two stops feeling like a mystery and starts looking like something you can see coming.
Why a profitable P&L and the bank balance differ
An accrual-basis P&L is built to measure earning, not the movement of money. Four mechanics pull the bank balance away from the profit figure, and they can operate at the same time.
Start on the revenue side. Revenue is recorded when it is earned, not when it is collected. When you complete the work and invoice it, the income statement recognizes the revenue, but the cash does not arrive until the customer pays. The distance between revenue you have booked and cash you have received is your accounts receivable, and for as long as that money is outstanding, it is profit on paper and nothing in the account.
The expense side works in the other direction. Expenses are recorded when they are incurred, not necessarily when they are paid, so the date an expense hits the P&L can differ from the date cash leaves the bank. Payroll runs on a fixed cadence no matter when customers pay. Vendor terms can push some material payments into later weeks while others are due quickly. Tax payments follow their own due dates. Each can move cash on a schedule that does not match when the related activity appeared on the income statement.
Investing cash flow is different again because it does not hit the income statement in the period the money leaves in the same way. When you buy a mower or a truck, the full purchase price goes out of the bank now. The P&L recognizes depreciation over the asset’s useful life rather than recording the full purchase as a current operating expense. The bank account absorbs the cash outflow much sooner than the P&L reflects the full economic cost.
Financing cash flow moves money in both directions without running through operating profit. Loan proceeds and draws on the line of credit put cash in the account, but they are not revenue; they are borrowed money you will repay. When you repay that debt, the principal portion leaves the bank without being an operating expense on the P&L. Owner contributions and owner draws also move cash without changing operating profit.
An illustrative example makes the timing concrete. Suppose a completed design/build job earns \$60,000 in revenue (illustrative figure). You invoice it the week the crew finishes, so the P&L books the \$60,000 and its margin right away. The customer pays on net-30 terms, and the cash arrives several weeks later. In the meantime you have already paid the crew that built it, settled material invoices that came due, and carried the overhead that ran the entire time. The profit was recorded when the work was done, but the cash to cover what the job consumed had to come from somewhere else until the payment landed.
So profit and cash measure two different things. Profit tells you whether the work you did earned more than it cost. Cash tells you when money actually moves, together with investing and financing flows that never appear as operating profit. A profitable business can therefore be short on cash in a given week even when the underlying work is economically sound.
What the 13-week cash forecast is, and what it is not
The tool that makes this visible is a 13-week cash forecast: a rolling, weekly, direct-method projection of the cash coming in and going out over the next quarter. Direct method means you build it from your own receipts and commitments, the cash you expect to collect and the payments you expect to make, rather than starting from net income and adjusting it. It is your money, week by week, based on what you know about receivables, payroll dates, vendor terms and fixed obligations.
It helps to be clear about what it is not. It is not the P&L, since it tracks cash timing rather than earning. It is not an annual budget divided into weeks. It is not a lender package built to support a financing request, and it is not a long-range model for multi-year strategy. It is the tactical layer beneath those tools, answering a narrower question: will the cash be there when the obligations arrive?
Thirteen weeks is one quarter. The horizon is long enough to expose a developing cash squeeze while still keeping the forecast at a useful weekly level. As the forecast reaches farther out, the exact timing of individual receipts and payments becomes less certain. A downloadable spreadsheet accompanies this Guide so you can build the weekly view without starting from a blank page.
How the forecast is built
The forecast rests on one equation applied to every week: Beginning Cash plus Net Cash Change equals Ending Cash. Week 1’s Beginning Cash is a required input, the real balance you are starting from. From there the weeks chain together, since each later week’s Beginning Cash is the prior week’s Ending Cash. A change in any single week therefore affects the weeks that follow.
Net Cash Change is not a single lump. The workbook keeps three components separately visible. Net Operating cash flow covers the money the business generates and spends running the work: recurring maintenance collections, project deposits and progress-billing collections, payroll on its actual cadence, materials and subcontractors, overhead, and taxes. Net Investing cash flow covers equipment and vehicle purchases and asset-sale proceeds. Net Financing cash flow covers loan and line-of-credit proceeds, principal repayment, and separate owner contribution and owner draw rows.
Entry follows one convention that keeps the arithmetic clear. You enter every amount as a positive number in a labeled row, and the workbook decides whether that row adds to or subtracts from cash. You do not type a negative sign in front of payroll or a debt payment; you enter the amount on the appropriate outflow row, and the structure handles the direction.
Each cash-flow line carries an Include? setting. Set it to Yes when that category applies to your business and No when it does not. Once a line is included, every week needs either an expected amount or a deliberate zero. A blank weekly cell means the amount is still unresolved, so the forecast marks the affected week INCOMPLETE rather than quietly treating the blank as zero.
Reading the forecast to find the tightest week
Once the weeks are built, read across the Ending Cash line and find its lowest point. That is the week to examine first, because it shows where the forecast puts the most pressure on available cash.
- Which expected collections are still uncertain?
- Which large payments are driving the low point?
- Is the pressure mainly operating, investing, financing, or timing?
- Which assumption would change the low point most if it moved?
The workbook includes one optional input, a single Minimum Cash Threshold. This is a management assumption: the floor you personally are unwilling to let the balance drop below. It is not a recommended reserve and it is not an industry benchmark. There is no universal reserve rule embedded here. The appropriate floor depends on your own obligations, seasonality, and tolerance for a tight week. Once you set a threshold, the forecast shows the headroom above it or the shortfall below it in each week.
A projected dip below your own floor is not a verdict; it is a prompt. Seeing it several weeks out gives you more time to respond before the tight week arrives, whether that means accelerating a collection, timing a deposit, deferring a discretionary purchase, or drawing on a facility deliberately rather than by surprise.
Keeping the forecast current
A 13-week forecast is only useful if it stays a 13-week forecast, so the cadence is weekly. As each week closes, replace its projected figures with the actual cash movements that occurred, then roll the window forward by adding a new week 13 on the far end. Revise the remaining weeks using the best information you now have and note meaningful forecast-to-actual differences so the next projection becomes better informed.
Use the Assumptions & Notes Log to distinguish Known amounts from Estimated amounts and to identify anything still Missing. That keeps uncertainty visible without turning it into a numeric confidence score.