The failures that matter are the quiet ones. A formula that has been reading the wrong column since someone inserted one. A query that returns nothing and looks exactly like a real answer of zero.
We reconcile what you maintain against what is true, report the drift, and flag the ambiguous cases instead of silently resolving them.
Every long lived spreadsheet drifts. Someone inserts a column and forty formulas quietly start reading the wrong field. A heading is reworded and a category flag defaults to one value for a year. A lookup fails and returns zero, which is indistinguishable from a real zero.
No one notices, because the report still runs and the number still looks plausible. Decisions get made on it. It surfaces eventually, and usually in front of someone whose opinion matters.
A number you can't rebuild from the transaction data is a number you can't defend. We build reports from the bottom up, so every figure traces line by line back to what happened.
Decide what the true source is before comparing anything. Half of all data disputes are two systems both believing they're the record.
Differences delivered side by side for review. Your staff entered that value for a reason, and you should see it before it disappears.
Not just what differs, but why. A column heading that was reworded is a completely different problem from a value someone typed wrong, and they need different fixes.
Reports constructed from transaction data, so any figure can be defended line by line when someone asks where it came from.
These almost always come up together. An audit that finds a process problem usually finds a data problem underneath it.
Every business is different, so we scope the audit that way. We spend time inside your operation and watch the work actually happen. You get a written map of every valley, what it costs you a year, and what it would take to flatten it. That document is yours whether or not we build anything.