A spreadsheet that only one person understands is a liability, even when every formula in it is correct.

I’ve opened workbooks where the logic was solid but nothing explained it. No labels on the assumptions, no note on where the data came from, and a hardcoded number in the middle of a formula that nobody could account for. The owner was out for a week, and the report stopped being usable.

Three small habits fix most of this:

- Put assumptions in labeled cells instead of burying them inside formulas

- Add a short “read me” tab covering the data source, the refresh steps, and what each sheet is for

- Name your ranges and tables so a formula reads like a sentence instead of a puzzle

None of it makes the spreadsheet more powerful. It makes it something a teammate can pick up on a Monday without calling you.

If your team’s key report lives in one person’s head, what would break first if that person went on vacation?