Most growing businesses can tell you what happened to their cash last month. Far fewer can tell you, with any confidence, what their cash position will look like 90 days from now. That gap is one of the most common — and most fixable — problems we see in finance functions that have outgrown their systems.
Why 90 days is the right horizon
A 30-day forecast tells you whether you can make payroll next month. A 90-day forecast tells you whether you can afford the decisions you're making right now — a new hire, a bigger inventory order, an acquisition opportunity. It's long enough to catch a problem while there's still time to act on it, and short enough that the numbers stay grounded in reality rather than becoming a loose annual guess.
What a reliable forecast actually requires
- A clear starting cash position, reconciled to your actual bank balances — not an estimate from your accounting system alone
- Receivables broken out by realistic collection timing, not just invoice due dates
- Payables and recurring obligations mapped to when they actually clear, not when they're booked
- A rolling update cadence — weekly or biweekly — so the forecast reflects what's actually happening, not what you assumed three weeks ago
The most common mistake
The businesses that struggle most with cash forecasting usually aren't missing data — they're missing a process. They have the numbers somewhere, spread across a bank feed, an accounting system, and a spreadsheet someone updates when they remember to. A forecast built that way is only ever as current as the last person who touched it.
A finance function that's kept pace with your growth treats the 90-day forecast as a living document, not a quarterly exercise — updated on a set schedule, owned by someone, and trusted enough that it actually drives decisions instead of getting built after the decision's already made.