One Source of Truth: End Spreadsheet Version Chaos

Somewhere, right now, a finance team is arguing about which spreadsheet is real.

Not which one is correct. Which one is real.

You know the scene:

• "Use the final file."
• "Which final file?"
• "The FINAL_final_v7 file."
• "Oh... I used FINAL_final_v7_revised."

This isn't a file problem. It's a source-of-truth problem.

When multiple versions of the same truth exist, you don't get better decisions. You get meetings.

The 4 rules of source-of-truth discipline

Rule 1: One canonical dataset

Whether it's a database table, a locked spreadsheet, or a structured export, your core transactions and balances should live in one canonical place.

Rule 2: Definitions are part of the dataset

If "revenue" depends on who is asked, it's not defined. Keep a definitions section alongside the data:

• Included and excluded items
• Recognition timing
• Source systems
• Owner of the definition

Rule 3: Changes require a log

You can still change things. You just can't change them invisibly.

• What changed?
• Why?
• Who approved?
• When?

Rule 4: Outputs are generated, not edited

If people manually edit the report output, the report stops being trustworthy. Keep the "raw" separate from the "presentation."

A practical implementation (that doesn't require a data warehouse)

Most teams can do this with a simple structure:

1. A canonical dataset (transactions table or locked "base" export)
2. A transformations layer (mappings, categories, rules) with versioned changes
3. A reporting layer (dashboards and exports) that reads from the same dataset

Version control isn't just for engineers.

It's for anyone whose job depends on truth.

Build one source of truth and your reporting stops being a debate.