The 13-week cash forecast that keeps companies alive

Profit is an opinion. Cash is a fact. The companies that survive downturns aren't the most profitable on paper — they're the ones that always know exactly when money comes in and goes out.

Your annual budget is useful for planning, but it's useless for survival. It's too coarse, updated too rarely, and built on accrual accounting that hides timing. The 13-week cash flow forecast solves this: a rolling, week-by-week view of actual cash movement over the next quarter. It's the tool turnaround specialists reach for first, because it answers the only question that ultimately matters — can we pay our bills?

Why 13 weeks?

Thirteen weeks is one quarter: long enough to see trouble coming, short enough to forecast each week with real accuracy. You update it weekly, always rolling the window forward, so you're never more than a few days from the truth.

What goes in it

• Starting cash — your real bank balance, not your book balance.
• Cash in — by week: customer collections (when they actually pay, not when you invoice), financing, other receipts.
• Cash out — payroll, rent, suppliers, taxes, debt service, one-offs.
• Net movement and ending cash — week by week, so you can see the lowest point.

The magic isn't the spreadsheet. It's seeing the week your cash dips lowest — weeks before it happens — while you still have options.

The three scenarios every forecast needs

A single forecast is a guess. Run three:

1. Base case — your honest expectation.
2. Downside — collections slip 20%, a big customer delays. This is your stress test.
3. Upside — what you do with surplus cash if things go well.

The downside case is the one that saves you. If it shows a breach, you act now — accelerate collections, delay non-critical spend, draw a facility — instead of discovering the problem the week payroll bounces.

Build one this week

Start simple: a spreadsheet with 13 week-columns, your real opening balance, and your known recurring inflows and outflows. Layer in customer-by-customer collection timing for your biggest accounts. Update it every Monday. Within a month it becomes the most-used number in your company.