How much cash will I have in three weeks? A working forecast

“How much cash will I have in three weeks?” — the question every project-business owner actually asks, in exactly those words — has a buildable answer: today’s true position, plus inflows you can point to, minus outflows already scheduled, rolled forward day by day. Not an average, not a vibe: a dated line that shows which week dips and whether it crosses your floor.

The reason the question stays unanswered in most businesses isn’t maths. It’s that the ingredients live in six places — two bank accounts, a PSP balance, an invoice ledger, a payroll date, a supplier pile — and the one person who could assemble them is “trying to stop getting burned on cash flow” with a spreadsheet that’s stale the moment it’s saved. Meanwhile the community wisdom is right: “most cash flow issues are billing timing errors.” The forecast is how you see them coming; the billing schedule is how you fix them.

Build it from facts, not averages

A working 30–90 day forecast has four layers:

1. The true position, today. Every bank account, every processor balance, and money in flight — the payout leaving tonight, the settlement landing Thursday. One number. If assembling it takes an hour, that’s the first thing to fix.

2. Inflows you can point to. Issued invoices with due dates — corrected by each client’s actual behaviour. The anchor client whose net 30 really pays in 45? Forecast 45. Stage payments go in on their milestone dates with realistic slip; retainers on the dates they historically collect. Hoped-for deals stay out — a forecast with optimism in it is a mood board.

3. Outflows already scheduled. Payroll and the contractor run on their dates, rent, supplier bills on due dates, and the lumpy quarterlies that ambush everyone: VAT, insurance, tax instalments. The £18k VAT bill is never a surprise on the calendar — only ever in the account.

4. The floor. The minimum balance you refuse to cross — a payroll cycle’s worth, for most. The forecast’s single most valuable output is a date: you’re heading below the floor on the 22nd. A dip you see three weeks out is a to-do list; the same dip on the day is a crisis.

Reading it: the shape, not the digits

Day-level precision is false comfort; the shape is the tool. The questions it answers:

• Which week dips? If the 15th–22nd trough recurs every month, that’s not bad luck — it’s a billing-timing error: costs scheduled ahead of the revenue that funds them.
• Which lever is cheapest? Seeing the dip early, you can chase the two invoices that close the gap, shift the supplier run a week (inside terms), or split a bill — each nearly free. The same gap discovered on the day gets solved with an overdraft or a factor, at a price.
• Can we afford the discount? Pay-early discounts and growth spends are cash-timing decisions. A forecast with a floor turns “can we?” from a feeling into a lookup.

The forecast that maintains itself

Everything above works and almost nobody sustains it, because the inputs change daily and the spreadsheet doesn’t. This is exactly the layer Fynex automates: the Cash view holds every account, PSP and in-flight movement in one live position, projects forward from movements it can point to — your issued invoices and their real collection behaviour, scheduled payouts, retainers, stage payments — and flags the date you’re heading below your floor while you can still act.

The levers live in the same place, which is the point: the agent that warns about the 22nd can also chase the invoices that fix it, hold a no-discount bill to its last safe day, and time the payout run cash-floor aware — with anything that moves money waiting for your approval.

“How much cash in three weeks?” is the whole game for a project business — profitable on paper and tight in the account is just that question going unanswered. Build the forecast from facts, give it a floor, and let it maintain itself: the businesses that get burned on cash flow aren’t the unprofitable ones, they’re the ones who found out on the day.