Due diligence predicts the business. The first 180 days after close test whether the prediction was ever true.
The post-deal period reveals what no data room, management presentation or expert session could fully anticipate: which employees actually leave (versus which management said might leave). Which customers actually churn (versus which the retention analysis said were secure). How working capital actually behaves when the seller is no longer managing it for a closing date. Whether the forecasts that supported the purchase price bear any relationship to the first two quarters of actual performance.
Track six variables across the first 180 days
Employee departures: Who left, from which functions, and was their departure anticipated in the integration plan?
Customer behaviour: Which customers reduced volumes, renegotiated terms, or moved to competitors? How does actual customer retention compare to the diligence projection?
Working capital: How does the working-capital position at 90 days post-close compare to the closing-date position? Has it reverted, and by how much?
Forecast accuracy: How do the first two quarters of actual performance compare to the forecasts in the investment committee memo?
Integration costs: Are actual integration costs tracking the original estimate, or have they escalated?
Hidden liabilities: Have any liabilities, obligations or commitments surfaced that were not identified during diligence?
In Northrop Management Private Limited’s transaction advisory practice, the post-deal truth test is a structured 180-day review that compares every material assumption in the investment thesis to the actual post-close evidence. The output is not a report card. It is a diagnostic that informs how the board evaluates, structures and governs future acquisitions.
Ashish Chaudhary, frames the learning principle directly: “Due diligence is a hypothesis about a business. Post-close evidence is the experiment that tests whether the hypothesis was correct. A company that never runs the experiment never learns from its acquisitions.”
Closing Implication
The post-deal truth test is not a retrospective exercise. It is a governance discipline. Every assumption tested, every variance documented, every surprise analysed becomes an input into the next acquisition’s diligence scope, the next deal’s synergy projections and the next negotiation’s price discipline.
