What is a cash flow forecast (plan de trésorerie)?

In practice, in France

The difference from the income statement is the whole point of the exercise: the income statement records a sale at invoicing, the cash flow forecast waits for collection. A business can show a profit and still run dry — it is the gap between the two that kills a company, not its profitability.

A useful forecast is rolling: it is extended by one period at each closing, rather than being built once a year and watched run out. And it captures the outflows that never pass through the income statement: loan repayments, VAT to be paid over, tax instalments, the business property levy. These are what dig the holes, and they are absent from the result.

In Odoo

The data already exists: customer and supplier payment schedules, loan maturities, reconciled bank balances. The forecast is built on top of them.

The work is not collecting the data but dating it correctly: a customer invoice does not enter the forecast on its theoretical due date but on the delay actually observed with that customer. This is where DSO becomes genuinely useful.

Common mistakes

• Building it on contractual due dates when the history says otherwise.
• Forgetting outflows outside the income statement — loans, VAT, local taxes.
• Building it once and never checking it against actuals, which prevents the assumptions from improving.