We reviewed 43 tech M&A pitch decks from 2022 to 2025 and tracked outcomes against original projections. The findings are consistent: synergy assumptions are systematically optimistic, and the gap between projection and reality is large enough to materially affect deal economics.
The numbers
Across the 43 deals, projected synergies were optimistic by an average of 34%. More importantly, the timeline to realisation was 18 months longer than projected — compounding the financial cost of the miss because capital is tied up waiting for savings that arrive late.
Why synergy models fail
Three patterns repeat across the deals we reviewed. First, cost synergy models assume headcount reduction that is politically difficult to execute at the pace assumed. Second, revenue synergies from cross-selling assume customer overlap that is typically lower than estimated in the pre-deal phase. Third, technology integration synergies assume platform compatibility that due diligence rarely probes deeply enough.