Topic hub
Cash Flow
Profit is an opinion. Cash is a fact with a date on it.
Cash flow problems rarely announce themselves. They build quietly through slow payers, lumpy costs, tax deadlines and growth that eats working capital.
This hub covers forecasting, reserves and the specific habits that stop a profitable business running out of money.
Written by Daniel, peer-reviewed by Marcus
Last reviewed:
Start here
Why Profitable Businesses Run Out of Cash
The timing gap explained with a worked example you can recognise.
Read the guideChoose your next move
A decision map for this topic
Start with the problem in front of you, then follow the related guide instead of reading the whole library at once.
I need a reliable near-term cash view
Build the existing 13-week view first, then maintain it as a rolling forecast.
Open the guide →Customers are paying too slowly
Measure debtor days and follow a structured late-payment sequence before treating the gap as a borrowing need.
Open the guide →The forecast shows a persistent shortfall
Use the warning-signs guide for an early, safety-first escalation route rather than masking the problem with credit.
Open the guide →Where it hurts
Common problems in this area
Pick the sentence that sounds most like your week.
“I never know how much I can safely spend”
Your balance includes money that already belongs to HMRC, suppliers and next month's payroll.
Where to start“Growth is making cash worse”
More work means more up-front cost, and the invoices land later than the bills.
Where to start“I want visibility further than next week”
A rolling 13-week view is the standard tool and it fits on one screen.
Where to startRead by job
Grouped guides with a clear purpose
These routes organise the most useful child guides by the decision they help you make; the complete library remains below.
Forecast and act early
Use these pages to build, update and stress-test a cash view without duplicating the detailed 13-week build.
- 13-Week Cash-Flow Forecast GuideWhy thirteen weeks is the exact right horizon for small business survival, what goes into the forecast, and how to roll it forward every Monday.
- Rolling Cash-Flow Forecast: keep the next decision in viewTurn a static cash plan into a weekly operating routine: replace estimates with actuals, extend the horizon and explain variances.
- Cash-Flow Scenario Planning: test the decision before the crisisUse base, delayed-receipt and downside cash scenarios to set early decision triggers before a shortfall becomes urgent.
Shorten the cash cycle
Improve the timing of customer receipts, supplier commitments and stock without assuming finance is the answer.
- Debtor Days: measure how long customers take to payCalculate debtor days, distinguish payment terms from cash collection, and set a calm, documented late-payment escalation process.
- Cash Conversion Cycle: how long cash is tied up in tradingUse inventory, customer-payment and supplier-payment timing to see how long trading cash is tied up and which operational lever to test first.
- Inventory and Cash Flow: buy enough stock without trapping cashPlan stock purchases, demand, lead times and slow-moving inventory so that availability does not silently become a cash-flow problem.
Complete library
All guides in Cash Flow
Guide
Why Profitable Businesses Run Out of Cash
Profit is an accounting opinion about a period; cash is a fact with a date on it. How to spot the gap between the two before it breaks a healthy business.
ExploreGuide
13-Week Cash-Flow Forecast Guide
Why thirteen weeks is the exact right horizon for small business survival, what goes into the forecast, and how to roll it forward every Monday.
ExploreGuide
How Much Cash Should a Business Keep?
The difference between your bank balance and your 'safe to spend' balance, and how to calculate a cash floor that protects your business.
ExploreGuide
Cash-Flow Scenario Planning: test the decision before the crisis
Use base, delayed-receipt and downside cash scenarios to set early decision triggers before a shortfall becomes urgent.
ExploreGuide
Debtor Days: measure how long customers take to pay
Calculate debtor days, distinguish payment terms from cash collection, and set a calm, documented late-payment escalation process.
ExploreGuide
Rolling Cash-Flow Forecast: keep the next decision in view
Turn a static cash plan into a weekly operating routine: replace estimates with actuals, extend the horizon and explain variances.
ExploreGuide
Cash Conversion Cycle: how long cash is tied up in trading
Use inventory, customer-payment and supplier-payment timing to see how long trading cash is tied up and which operational lever to test first.
ExploreGuide
Financial Distress Warning Signs: act while options remain
Recognise early cash, trading and operational warning signs, gather the right evidence, and seek appropriate qualified support before obligations are missed.
ExploreGuide
Inventory and Cash Flow: buy enough stock without trapping cash
Plan stock purchases, demand, lead times and slow-moving inventory so that availability does not silently become a cash-flow problem.
ExploreGuide
Working Capital: the cash tied up in growth
Understand working capital, the cash conversion cycle and the operating levers—debtors, suppliers and stock—that determine whether profitable growth can be funded.
ExploreSubtopics
What this hub covers
Forecasting
13-week rolling forecasts, scenarios and what to do when the line goes negative.
Reserves
Emergency funds, tax pots and how much is genuinely enough.
Working capital
Debtor days, supplier terms and stock or subcontractor timing.
Seasonality
Planning for irregular income without panic borrowing.
Featured tool
13-Week Cash-Flow Forecaster
Enter opening balance, expected receipts and payments, and see the weekly low point.
Open the toolFree checklist
Weekly cash checklist
Fifteen minutes, same slot every week.
- Update the actual closing balance
- Mark invoices paid and chase anything over terms
- Add any new committed costs to the forecast
- Confirm the next three weeks stay above your floor
- Move the tax percentage of receipts into the tax pot
Frequently asked questions
- Why 13 weeks?
- It is one quarter — long enough to see a VAT or payroll cliff coming, short enough that your estimates are still credible.
- What if my income is completely unpredictable?
- Forecast conservatively on receipts and accurately on costs. The point is to find the low point, not to be right about the high point.
Keep reading
Related guidance
How Cash Flow connects to the rest of the site, and what to read alongside it.
Do this next
Next steps in Cash Flow
- 1
Read Why Profitable Businesses Run Out of Cash
The timing gap explained with a worked example you can recognise.
Read the guide - 2
Run the 13-Week Cash-Flow Forecaster
Enter opening balance, expected receipts and payments, and see the weekly low point.
Open the tool - 3
Score your whole financial setup
Ten areas in about five minutes, with a seven-day and 30-day plan you can print.
Start the check-up - 4