Why FP&A Teams Need a Single Source of Truth for KPIs

If you run FP&A at a growing business, you know the feeling: it's the week before the board meeting, and three different versions of the same KPI are floating around in three different spreadsheets. Revenue is £4.1m in the CFO's deck, £4.0m in the ops report, and £4.15m in the analyst's model. Nobody is lying — the numbers just come from different sources, with different cutoff dates, different adjustment methodologies, and different people who last touched them.

This is the version control problem that kills FP&A productivity. And it's entirely avoidable.

What a single source of truth actually means

A single source of truth (SSOT) for KPIs is not a dashboard. It's not a BI tool. It's the upstream data — the agreed, approved, auditable record of what each business metric is, at each point in time, owned by a specific person who signed off on it.

Everything downstream — board packs, investor updates, management accounts, forecasts — pulls from that one authoritative record. There's no reconciliation step because there's nothing to reconcile.

The hidden cost of not having one

Most FP&A teams don't track how long they spend on reconciliation and version management. If you did, the number would be alarming. Common symptoms:

• Pre-board "number-checking" calls that eat half a day every month
• Spreadsheets emailed as attachments, overwritten by different users
• KPI definitions that quietly shift between quarters
• Data corrections that are made in one place but not others
• No audit trail for why a number changed between reporting periods

Beyond the time cost, there's a credibility cost. When a board member or investor spots a discrepancy — even a small one — it raises questions about data quality that take much longer to resolve than a clean number would have.

What makes an SSOT work in practice

A genuine single source of truth for KPIs needs three things:

• Structured data entry — KPIs are entered in a defined format, with defined fields, not free-form into a spreadsheet that anyone can reshape
• A review and approval workflow — numbers are submitted, reviewed, and signed off before they become "official", with a record of who did what and when
• An audit trail — every change is logged, so you can always explain why a number is different from last month's version

Most finance teams try to build this out of spreadsheets and email. It can work at small scale, but it breaks down quickly as the business grows, the number of datasets increases, and more people need access.

How FP&A teams are solving this

The shift happening in forward-thinking FP&A teams is the separation of data storage from data presentation. The KPI record — the single source of truth — lives in a dedicated system with access controls, review workflows, and an audit log. Analysis and presentation (charts, commentary, decks) happen in the tools teams already love: Excel, Google Slides, Power BI. But they pull from the one clean source, not from each other.

This is the model Truenumb is built on. Finance teams create structured datasets for each KPI category, assign reviewers, approve data submissions, and export board-ready outputs — without replacing the tools they already use.