1. Separate cost, funding and availability
Make three lists. First, list costs including taxes: contractors, studies, supplies, delivery and associated expenses. Second, identify funding and its status: available, agreed with conditions, requested or merely considered. Third, record when each sum can actually enter or leave your account. Keep the quotation, invoice, notification or schedule supporting each amount.
2. Link each payment to a documented stage
Use the terms of your contract rather than a universal deposit percentage or a rule from a different type of contract. Ask what triggers each payment and who confirms that the relevant stage has been reached. Check whether studies, directly ordered supplies, transport and reinstatement are already included. A change in scope should also be reflected in the budget and payment calendar.
3. Confirm when expected funds become available
For each source of funds, record the amount, conditions, supporting documents, announced timing and contact. Sending an application does not make the money available. Ask the funding body or lender how payment will work in your case. If a date is unknown, keep it marked as unknown and consider different timing scenarios. A cash-flow calculation does not establish grant eligibility, loan approval or contractual payment terms.
4. Calculate the tightest point, movement by movement
Start with money already available, add incoming funds when available, and subtract each payment when due. The lowest balance shows the temporary shortfall to cover. Do not offset an early-month bill against a late-month receipt without considering the gap. Our four-stage tool is an initial planning aid: use a more detailed calendar when several movements occur within one stage.
Fictional example: start with €5,000, pay €8,000, then receive €8,000 and pay €5,000. The final balance is zero, but €3,000 is temporarily missing. A negative balance signals a planning issue; it does not authorise an overdraft.
5. Update the calendar when decisions change
Compare forecasts with actual costs and dates after each confirmed change. Record extra work, delayed delivery, new payment dates and funds received. Keep the previous version and date your revised assumptions. Discuss timing problems before the due date; do not assume that you can postpone payment unilaterally. Before a new order, check the balance remaining after commitments already made.
The information to collect
- Costs including taxes, linked to quotations and direct purchases.
- Available funds separated from expected resources.
- Confirmed conditions and timing of incoming funds.
- Payments and receipts placed in their actual order.
- The lowest balance and any temporary shortfall.
- Unknown assumptions retained and the calendar updated.
Use the calculation and verify the contract
Open the cash-flow calculator and CSV export (French). Its inputs stay in your browser. Zero means no payment or receipt at that stage; it should not replace an unknown amount.
The arithmetic is a planning method. Applicable payment terms remain those of your contract. Service Public: quotations and contractual commitment (French).