The spreadsheet that quietly started running the business
One person's scratch pad became the thing three systems and a payroll number depended on. I've walked into this more times than I can count. Here's how it happens and how to find yours before it burns you.
I do this for a living — I get called in when the data estate is on fire — and there’s one thing I find in almost every business I touch. A spreadsheet. Not a normal one. The one that quietly started running part of the company while nobody was looking.
It always starts the same way. One person, one afternoon, a quick way to track something the “real” system couldn’t do yet. It was never meant to last. Then it did.
The last one I found had a commission calculation in it. Fine, whatever. Except a Zapier automation was reading a cell out of it every hour and pushing that number into the CRM. And someone else had built a report on top of it that the founder actually trusted and quoted in meetings. None of this was written down. None of it was anyone’s job. Then the person who made it reordered a column, and the whole thing started lying to everyone at once.
Why I’m not mad at the spreadsheet
Let me be clear: the spreadsheet isn’t the problem. Spreadsheets are incredible. I’d defend them all day.
The problem is that a spreadsheet has no idea it’s important. It won’t warn you. It won’t throw an error. You can paste over a formula, reorder a column, filter and forget, and it will keep spitting out a number the entire time. The number is just wrong now. And you won’t find out until it’s expensive.
That’s the whole thing. A real system tells you when it breaks. A spreadsheet that grew into a system tells you nothing, because it doesn’t know what it became.
How to find yours
You don’t need to audit everything. Ask three questions.
- Does something read it automatically? If an automation, a script, or a scheduled job touches it, it stopped being a document. It’s an interface now. And cell B7 is a terrible interface.
- Does a number leave it and enter a decision? Payouts, forecasts, the figure the founder repeats to the board. Trace where that number is born.
- What happens if the person who made it leaves? If one human is the only one who understands it, that’s not a spreadsheet. That’s a single point of failure in a costume.
What I actually do about it
Not “rebuild it in a database.” That’s the panic move, and I’ve watched people burn three months rebuilding something that was working fine. Don’t.
Make the important ones loud instead. Add a reconciliation check — a second number, from a different source, that should always match the first and screams when it doesn’t. Lock the columns other things depend on. And write one plain-English paragraph at the top: what this is, what reads it, what breaks if you touch it. That paragraph is worth more than any migration you’re imagining.
The goal was never to kill the spreadsheet. It’s to know you have one, and to make sure the day it breaks is a day you hear about it — not a quarter later, in a number that was quietly wrong the whole time.
If you’ve got one of these, you already know exactly which one I mean. Go read it before it reads you.