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13-Week Cash Flow

Visor Studio · FP&A · Generated September 21, 2026

13-Week Cash Flow

Direct-method rolling forecast — weekly inflows, outflows, ending balance, line-of-credit need.

Starting position

Weekly flows

W1W2W3W4W5W6W7W8W9W10W11W12W13
A/R collections
Other inflows
A/P payments
Payroll
Rent
Taxes
Other outflows

Result

Trough cash
$2,050,000
Trough week
W1
LoC needed
$0
LoC headroom
$5,000,000
WeekInflowsOutflowsNetEnding cash
W1850,000800,00050,0002,050,000
W2850,000800,00050,0002,100,000
W3850,000800,00050,0002,150,000
W4850,000800,00050,0002,200,000
W5850,000800,00050,0002,250,000
W6850,000800,00050,0002,300,000
W7850,000800,00050,0002,350,000
W8850,000800,00050,0002,400,000
W9850,000800,00050,0002,450,000
W10850,000800,00050,0002,500,000
W11850,000800,00050,0002,550,000
W12850,000800,00050,0002,600,000
W13850,000800,00050,0002,650,000

What it calculates

A 13-week cash flow is a rolling short-term forecast of every cash receipt and payment, built directly from expected transactions rather than derived from the income statement. It is the standard tool for managing liquidity when cash is tight.

How it is calculated

It uses the direct method: list expected collections by week from the receivables ledger and expected disbursements from payables, payroll, debt service, tax and capital spending. Each week's ending balance carries into the next as the opening balance. The rolling element matters - each week the forecast is re-cut with one more actual week and one more forecast week, so it never goes stale.

How to read the result

The number to watch is the minimum balance across the horizon, not the ending balance. A forecast that ends comfortably but dips below zero in week seven is a forecast of insolvency in week seven. Compare each week's actual to what you forecast: forecast accuracy is the real output early on, because a 13-week model nobody trusts is worse than none. Where the trough breaches the minimum operating balance, the gap is the amount of facility you need to arrange in advance.

Worked example

Opening cash of 800,000, weekly collections averaging 420,000 and disbursements averaging 465,000 drains roughly 45,000 a week. Payroll of 260,000 in weeks 2, 6 and 10 and a 300,000 tax payment in week 9 push the week-9 balance to about 95,000 - above zero, but well below a 250,000 minimum operating balance.

Common questions

Why 13 weeks specifically?
It is one quarter, long enough to see a full cycle of payroll, rent, tax and debt service, and short enough that weekly detail is still knowable rather than guessed. It is also the horizon lenders and restructuring advisers conventionally expect.
Why the direct method rather than the indirect?
The indirect method starts from net income and adjusts for non-cash items, which is fine for annual reporting but cannot tell you what clears the bank next Thursday. The direct method forecasts the actual receipts and payments, which is the only useful basis at weekly granularity.
How should uncertain collections be handled?
Apply a collection probability by customer or ageing bucket rather than assuming everything arrives on terms. Then run a downside case where the slowest payers slip another two weeks - the trough in that case, not the base case, is what you should size a facility against.

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