Liquidity is the one metric whose absence can bring a healthy company to a standstill within weeks. A profitable business model is no protection: if receivables arrive later than payables fall due, a gap opens that no profit-and-loss statement shows. Germany's Federal Statistical Office recorded 24,064 corporate insolvency filings for 2025, an increase of 10.3 percent year on year.[1] Behind many of these cases lies not a demand problem but a lack of foresight about one's own solvency.
The most effective remedy is unspectacular: a rolling 13-week liquidity plan. It is short enough to maintain weekly and long enough to spot bottlenecks before they become acute.
Why exactly 13 weeks
Thirteen weeks equal a quarter. This horizon captures the period in which most cash flows are already known or can be estimated well: open receivables with their due dates, fixed costs such as payroll and rent, planned investments, tax and loan repayment dates. Shorter plans miss the next large item; much longer ones lose accuracy and turn into a budgeting exercise rather than a steering tool.
Building it step by step
- Set the opening balance. Start with the actual bank balance across all accounts on the cut-off date, not the book balance.
- Schedule inflows. Enter open receivables by realistic payment date, not invoice date, and reflect each customer's actual payment behaviour.
- Capture outflows. Payroll, rent, suppliers, tax, loan repayments and leasing, week by week and by due date.
- Roll the weekly balances. Each week's closing balance becomes the next week's opening balance, creating the rolling forecast.
- Add scenarios. At least one conservative case, such as delayed inflows or a drop in revenue, shows how robust the plan is.
A robust 13-week plan contains:
- the actual opening balance per bank account
- inflows by expected receipt, not invoice date
- fixed costs, payroll and suppliers by due date
- tax, loan repayments, leasing and planned investments
- a minimum-liquidity line as a trigger to act
- one conservative counter-scenario
Maintenance matters more than perfection
A liquidity plan is not a one-off document but a weekly ritual. What matters is not the first version but the continuously updated one: each week the elapsed week is replaced with actuals and a new week is added at the front. Comparing plan against actuals builds, over time, a reliable sense of your own forecast quality — and that quality is the real value.
At an owner-managed industrial supplier (18 employees, Northern Germany), liquidity data was scattered across Excel and bank statements. After building a rolling 13-week plan and a fixed weekly rhythm, liquidity forecast accuracy rose from around 63 to 98 percent; monthly reporting was ready on the 3rd working day instead of the 12th. Figures from internal management data, released for publication.
Common mistakes
- Invoice date instead of payment date. Planning receivables by invoice date plans too optimistically.
- Only one scenario. Without a conservative case the risk stays invisible.
- Maintained too rarely. A weekly plan updated monthly is not a weekly plan.
- No trigger line. Without a defined minimum, action comes too late.
Used well, the 13-week plan shifts decisions from reaction to foresight: receivables are chased earlier, payment terms negotiated and investments timed before things get tight.
Sources
- Federal Statistical Office of Germany (Destatis): Corporate insolvencies in 2025: +10.3 % year on year. Press release No. 085 of 13 March 2026.