Why 12 months and not 3

Three months is your monthly view. It's the Excel view. It tells you what's going out next month.

Twelve months is your strategic view. It tells you:

  • When do I need to start prospecting hard? (3-4 months before the current mission ends — not the month it stops)
  • Can I afford a €3,000 training in September? (the forecast shows the actual impact on your runway)
  • If I take 4 weeks off in August, am I still OK?
  • Which month is the semi-annual VAT going to wreck me?

Without that view, you're flying blind. With it, you make decisions 6 months ahead.

The 5 key inputs of a forecast that holds up

  1. Confirmed missions — day rate × billable days × payment probability
  2. Recurring expenses — subscriptions, rent, SaaS tools
  3. Planned one-off expenses — equipment, training, travel
  4. Social charges — actual calendar (URSSAF/CIPAV in France, HMRC in the UK, Finanzamt in Germany) with the right months
  5. VAT collected vs deductible — monthly or quarterly depending on regime

The trap that breaks 80% of Excel forecasts

Freelancers who forecast in Excel get caught by the same thing every time: they forget the lag between invoicing and getting paid.

You invoice €5,400 in June. Your client pays on 45 days. So the cash hits end of July, maybe August. And meanwhile, you've still paid OVH, the accountant, and your social charges.

In a good forecast, revenue lands on the projected cash-in date, not the invoice date. And ideally with a safety margin (10% late payments is realistic).

Realized vs projected: the view that changes everything

Once a month is past, you don't want to see projected numbers anymore — you want to see what actually happened. This realized vs projected duality is what turns a forecast into a true cockpit:

  • Past months: only real flows (paid invoices, settled expenses, paid charges)
  • Current month: a mix of realized + projected for the remainder
  • Future months: full projection

This asymmetry matters. Without it, your "real treasury" is polluted by assumptions that never materialized.

When to automate

The moment you have:

  • 2+ missions in parallel
  • 1+ VAT return per year
  • 3+ recurring expenses
  • 1+ vacation planned

… keeping this in Excel becomes a real mental load. Every adjustment (mission slipping a month, surprise expense) means redoing 12 cells.

That's exactly when you start winning by moving to a dedicated tool.