Why Due Diligence is Crucial for M&A Deal Success
Around 70% of M&A deals destroy shareholder value, and weak due diligence is the most cited cause. Strong due diligence runs across six tracks — financial, tax, legal, operational, commercial, and HR — and feeds findings back into the deal structure through price cuts, escrows, or earn-outs.
Most people think the hard part of mergers and acquisitions is finding the right target and agreeing on a price. The truth is the opposite — finding and pricing a deal is the easy part. The hard part is what happens between the term sheet and the closing, when due diligence either uncovers the things that kill a deal or, more dangerously, fails to uncover them. Roughly 70% of M&A deals destroy shareholder value, and weak due diligence is named as the single biggest reason in study after study.
Due diligence is not a paperwork exercise. It is the moment when the buyer’s instincts, story, and excitement get tested against actual numbers, contracts, and culture. Skip it or rush it, and the consequences arrive in the first quarterly result after closing.
The pain point — what bad due diligence looks like
Picture an Indian listed company acquiring a private business for 1,000 crore rupees. The target had clean audited financials, a charismatic founder, and growing revenue. Six months after closing, the buyer discovers:
- 30% of revenue was customer concentration with one client whose contract was not renewed.
- Two key engineers left within 90 days of closing.
- An ongoing tax dispute worth 80 crore was not properly disclosed.
- Receivables included aged balances written up just before the sale.
Suddenly the 1,000 crore deal is worth 600 crore. The buyer’s share price drops 15%. The CEO is asked to explain to investors how this slipped through. None of it was hidden — it was all there in the data room. It just wasn’t looked at carefully enough.
Bad due diligence is not the absence of information; it is the failure to ask the right question of the information you already have.
Diagnosing why due diligence fails
Three reasons account for most due-diligence failures in Indian M&A.
1. Time pressure from deal momentum
Once a term sheet is signed, both sides want to close fast. The buyer’s board is told the deal is happening; analysts have been briefed; everyone is in commitment mode. This momentum compresses the diligence window from the ideal 8-12 weeks to a rushed 3-4 weeks.
2. Focusing on financials and ignoring everything else
Financial due diligence is the easiest. You hire one of the Big Four, they audit the books, they produce a 200-page report. Done. But financial diligence catches only the financial issues. It misses cultural mismatch, hidden HR liabilities, IT infrastructure debt, regulatory risk, and customer concentration.
3. Trusting management representations without verification
Sellers describe their business in the best light. A buyer’s job is to verify, not to believe. “Our top 5 customers are stable” should be tested by reading customer contracts, calling references, and checking renewal history — not by accepting the seller’s word.
The fix — a structured due diligence checklist
Strong due diligence covers six tracks, each owned by a specialist.
Financial diligence
- Revenue quality — recurring vs one-time, customer concentration, churn.
- Working capital normalisation — actual cash needed to run the business.
- EBITDA adjustments — strip out one-offs and related-party transactions.
- Debt-like items — capital leases, deferred revenue, gratuity provisions.
Tax diligence
- Direct and indirect tax assessments — closed and pending.
- Ongoing disputes and contingent liabilities.
- Transfer pricing for related-party transactions.
Legal diligence
- Material contracts — customer, supplier, employment, lease.
- Litigation — plaintiff and defendant cases.
- IP ownership — patents, trademarks, software.
- Regulatory licenses and compliance status.
Operational diligence
- Manufacturing capacity vs claimed utilisation.
- Supplier dependencies — single-source risks.
- IT systems — age, scalability, technical debt.
- Quality systems and certifications.
Commercial diligence
- Market size validation through independent sources.
- Competitive positioning — customer interviews.
- Pricing power and elasticity testing.
HR and cultural diligence
- Key employee interviews and retention risk.
- Compensation benchmarking.
- Cultural fit assessment — often the silent dealbreaker.
How to structure the diligence work
Two practical rules separate good buyers from great ones.
- Allocate 60-90 days for diligence. If the seller refuses, that itself is a red flag. A serious target understands the buyer needs time.
- Use independent advisers, not just internal teams. The buyer’s own team has incentive bias — they want the deal to happen because they have already presented it to the board.
How to use diligence findings to renegotiate
Diligence is not just a yes/no decision. The findings should feed back into the deal structure:
- Material findings: renegotiate purchase price.
- Specific risks: structure earn-outs or escrows.
- Tax disputes: indemnify with cap and time limits.
- Key personnel risk: lock retention agreements as a condition precedent.
Preventing the same mistakes next time
Companies that consistently do M&A well have three habits:
- A standardised diligence playbook updated after every deal.
- A post-mortem review six months after each closing — what was missed, why, what should be added next time.
- An integration team that is involved in diligence, not handed the deal at closing.
This builds institutional learning. Without it, every deal repeats the previous deal’s mistakes.
Due diligence is the cheapest insurance available in any M&A transaction. Skipping it to save 1-2% of deal cost regularly destroys 20-50% of deal value within two years. The Securities and Exchange Board of India’s Substantial Acquisition of Shares and Takeovers Regulations and disclosure rules relevant to listed-company M&A are published at sebi.gov.in.
Frequently Asked Questions
- What is due diligence in M&A?
- Due diligence is the structured investigation a buyer conducts before closing an acquisition, covering financial, tax, legal, operational, commercial, and HR aspects of the target. It typically runs 60-90 days.
- What is the biggest cause of M&A failure?
- Weak or rushed due diligence is consistently named as the largest single cause. Hidden tax disputes, customer concentration, key-employee risk, and cultural mismatch surface only when diligence is shallow.
- How long should due diligence take?
- A serious M&A diligence exercise takes 8-12 weeks across all six tracks. Sellers who push for closure within 3-4 weeks usually have something they would prefer not to be examined.
- How do diligence findings affect the deal price?
- Material findings can trigger price cuts, escrow holdbacks, indemnities, earn-outs tied to performance, or specific conditions precedent like retaining key employees. Diligence is the buyer’s primary lever for re-pricing risk.