A spreadsheet has no way to say “I don’t know.” A blank cell in a sum counts as zero. That small fact causes a surprising amount of bad financial planning.
How it goes wrong
Imagine a cash forecast where next month’s payroll hasn’t been entered yet because the new hire’s salary isn’t final. The cell is blank. The total treats it as zero. The forecast shows a comfortable balance, someone approves an equipment purchase on the strength of it, and three weeks later the business is short.
Nobody made a calculation error. The model simply couldn’t distinguish “nothing” from “not known yet.” Variations of this happen everywhere, including a missing customer payment date, an unmapped account in an import, or a department that didn’t submit its numbers.
The rule
When we built PursuitBid, we adopted one rule that shapes most of the product: missing values are never treated as zero.
That means:
- Required inputs are checked before they feed a calculation.
- When something is missing, the calculations that depend on it say so, rather than producing a confident number.
- Reports keep three things visibly distinct, namely recorded results, management’s assumptions, and gaps.
- Earlier saved versions keep the source context they were produced from.
Why it’s worth the friction
The rule is slightly inconvenient. A forecast with a flagged gap is less satisfying than a clean chart. But the alternative is a number that looks precise and is wrong, and decisions get made on it.
In our experience, the conversations improve too. “We can’t project week seven until we know the hire’s start date” is a useful thing for a management team to hear. It turns an invisible assumption into a decision someone owns.
Apply it in your own spreadsheets
You don’t need special software to adopt the principle:
- Use a visible marker such as “TBD” or a colored cell for unknowns instead of leaving them blank.
- Add a check that counts unknowns and shows the count at the top of the model.
- Don’t publish a forecast with unknowns without saying so.
The point isn’t perfect information. It’s being honest about what you don’t know yet.
Written by Syntonyl team. This article is general information, not legal, tax, or financial advice.