Why your spreadsheet is now a liability
There's a tipping point where the spreadsheet that built the business starts to put it at risk. Here are the five signs you've passed it.
Spreadsheets are the most underrated software in the world. They've launched entire businesses. But every spreadsheet has a useful life , and the symptoms of having outgrown one are remarkably consistent.
To be clear: this isn't an anti-spreadsheet piece. We use them every day. The argument is narrower , there's a specific category of spreadsheet, the one your operations depend on, that quietly becomes a serious risk past a certain size. These are the symptoms.
The five signs
1. One person can break the company. If "the master sheet" lives on one laptop, or only one person knows which tab is the real one, you're one resignation away from a crisis. Bus-factor of one is fine for a side project. It's not fine for the system that calculates payroll.
2. Two versions of the truth. Sales says one number, finance says another, both pulled from "the" spreadsheet. They're both right , and that's the problem. Each team has a copy with their own tweaks, and reconciling them is now somebody's monthly job.
3. Daily admin to keep it alive. Copy-paste between sheets. Manual reconciliation. End-of-month cleanup that takes a person two days. That's a salary, not a spreadsheet. We've seen clients paying the equivalent of £30k–£60k a year in human time to keep a single sheet running.
4. It's open all day. When a tool is open in 12 browser tabs across the team, it has graduated from "document" to "application". Time to treat it like one. Documents get edited, saved, closed. Applications need permissions, audit trails, validation and uptime.
5. You're afraid to change it. When nobody dares touch the formulas because something downstream will break, you've built a legacy system. Just in Excel. The first sign is people CC-ing each other before making a change. The second is people stopping making changes at all and working around the sheet.
The hidden sixth sign
Compliance. The moment a regulator, an auditor, a customer's procurement team or an insurer asks you to produce an audit trail of who changed which value when, the spreadsheet is no longer a fit. Version history in cloud sheets helps, but it's not a substitute for proper change logs.
What to do
You don't have to replace the spreadsheet overnight. Start by identifying which slice causes the most risk , usually the bit with money, customers, or compliance attached , and move just that. The rest can live in Excel for a long time yet.
A practical migration we've done a dozen times: keep the spreadsheet exactly as it is, build a small bespoke app that owns the one risky slice (say, customer records), and have the spreadsheet pull that data via an export. The team's workflow barely changes on day one , but the source of truth has moved, and the next slice gets easier.
When the spreadsheet wins
Don't migrate everything. Spreadsheets remain excellent for: one-off analysis, modelling scenarios, the budget you redo each quarter, anything where the structure changes more often than the data. Build apps for the things that are stable and operationally critical. Keep sheets for the things that are exploratory and personal.