Tax Due Diligence in M&A India 2026: Income Tax, GST, TDS & Deal Checklist
Tax due diligence in M&A India is the process of identifying, quantifying and transaction-mapping tax exposures before an acquisition, investment, fundraising or other deal closes. In 2026, the exercise deserves extra care because India moved to the Income-tax Act, 2025 from 1 April 2026, while earlier periods and proceedings can continue under the Income-tax Act, 1961. A useful diligence review therefore does more than list notices: it reconciles returns to books, tests positions and documentation, separates crystallised liabilities from contingent risks, and shows the deal team which issues may require a price adjustment, specific indemnity, escrow, covenant or post-closing action.
Tax due diligence in India: what changes in 2026?
The most important current-year point is the direct-tax transition. CBDT confirmed that the Income-tax Act, 2025 came into force on 1 April 2026 and replaced the 1961 Act for income from Tax Year 2026-27 onwards. At the same time, the department has clarified that the old Act continues to govern periods beginning before 1 April 2026 and proceedings relating to those earlier years. For a transaction team, this means a target company can simultaneously have current-period compliance under the new Act and historical assessments, appeals, demands or return positions under the old Act.
Official references: CBDT press release on the Income-tax Act, 2025 effective from 1 April 2026; Income Tax Department transition guidance.
What a buyer or investor should actually test
A transaction-focused tax review should begin with the deal perimeter and the years that matter. The reviewer should map legal entities, business lines, locations, tax registrations, ownership changes, material restructurings and significant related-party or cross-border transactions. Only then should the review move into returns, assessments and exposures. This prevents a common diligence failure: collecting hundreds of tax documents without linking them to the economics of the transaction.
1. Direct-tax compliance and historical positions
Reconcile filed income-tax returns to audited financial statements and tax computations for the review period.
Identify open assessments, reassessments, appeals, rectification matters, outstanding demands and refunds, and obtain the underlying orders rather than relying only on management summaries.
Review material deductions, exemptions, brought-forward losses, depreciation positions and transaction-specific tax treatments that affect sustainable cash tax.
Map uncertain or aggressive positions to the relevant period under the 1961 Act or the 2025 Act instead of mixing the two frameworks.
Check whether tax provisions in the accounts reasonably reflect known proceedings and whether contingent disclosures reconcile to the diligence schedule.
2. TDS and withholding-tax diligence
Withholding-tax failures can create a combination of principal tax, interest, disallowance or penalty exposure depending on the facts and the applicable law. Diligence should therefore compare ledgers and major expense classes with TDS returns, challans and certificates; test recurring vendors and high-value payments; and focus on areas such as professional services, contract payments, rent, interest, commission, non-resident payments and year-end provisions. The objective is not to re-perform every compliance entry, but to identify systematic exceptions and quantify a defendable exposure range.
3. GST diligence: returns, ITC and business-process risk
GST diligence should be tied to operational data rather than limited to return filing status. A buyer should understand whether outward supplies, credit notes, e-invoicing/e-way bill processes where applicable, input tax credit, reversals, place-of-supply positions and classification practices are consistent with books and contracts. CBIC’s input-tax-credit framework requires documentary support and prescribed conditions for credit. In diligence, recurring ITC mismatches, unsupported credits, blocked-credit issues, unusual reversals or large unreconciled differences between accounting data and GST filings can indicate both tax exposure and weak finance controls.
Official GST reference: CBIC input tax credit rules and documentary requirements.
4. Transfer pricing and cross-border transactions
Where the target has associated-enterprise or cross-border dealings, tax diligence should test whether the transaction universe is complete, agreements support the actual conduct, pricing documentation exists, and positions reconcile with the financial statements and tax filings. The Income Tax Department’s transfer-pricing guidance confirms that international transactions with associated enterprises are evaluated against the arm’s-length principle and that documentation obligations apply to covered transactions. For deal teams, the key issue is not merely whether a report exists; it is whether a material adjustment, guarantee, loan, receivable, service charge, royalty or restructuring position could create a historical or recurring tax risk.
Official reference: Income Tax Department transfer-pricing guidance.
5. Tax litigation and contingent liabilities
A tax demand is not automatically equal to the economic exposure that should be deducted from purchase price. The diligence team should understand the issue, amount demanded, amount already paid, appellate stage, legal merits, precedent, management position, adviser view and expected timing. The output should distinguish crystallised liabilities, probable exposures, reasonably possible matters and remote items, while avoiding false precision. The transaction response can then be matched to the risk—price adjustment for a near-certain liability, specific indemnity for an identified historical exposure, escrow for a material unresolved matter, or a covenant where remediation is required before closing.
Worked mini-case: how tax diligence changes the deal discussion
Assume an Indian target reports annual EBITDA of ₹40 crore and the parties are negotiating an enterprise-value-based acquisition. During tax diligence, the review identifies three items: ₹70 lakh of GST input credit requiring stronger support, ₹40 lakh of potential TDS exposure across recurring vendor payments, and a ₹1.2 crore historical direct-tax demand that is already under appeal. It would be poor diligence to simply deduct ₹2.3 crore from equity value. Instead, each item should be assessed on facts, probability, recoverability and contractual allocation. The GST item may require document remediation or a specific indemnity; the TDS pattern may justify an exposure estimate and control fix; the appealed demand may require an escrow or indemnity depending on merits. The value of tax diligence lies in converting tax facts into transaction decisions.
Tax due diligence checklist for M&A, fundraising and pre-IPO transactions
Define the legal-entity perimeter, review period and materiality thresholds before opening the data room.
Obtain income-tax returns, computations, audited financial statements, tax audit reports where applicable, assessment orders, appeal papers and demand/refund data.
Reconcile tax-return numbers to books and investigate recurring or large differences.
Review TDS/TCS compliance using ledger-level sampling and focus on systematic exceptions rather than isolated clerical items.
Reconcile GST registrations, returns and financial data; test ITC support, reversals, classification, place of supply and major notices.
Review related-party and cross-border transactions together with transfer-pricing documentation and agreements.
Identify tax attributes such as losses, credits and incentives that the valuation model assumes will be usable, and test the conditions underlying that assumption.
Create a complete litigation schedule showing issue, period, amount, stage, payment/deposit status and management/adviser position.
Separate one-time historical exposures from recurring tax-cost or control issues that affect normalized cash flows.
Map every material finding to a transaction response: price, net debt/debt-like treatment where appropriate, indemnity, escrow, condition precedent, covenant or post-closing remediation.
Common red flags transaction teams should not ignore
Large differences between revenue in financial statements and indirect-tax reporting without a clear bridge.
Material input tax credit balances or reversals that cannot be supported by invoice-level evidence.
Repeated late or revised filings suggesting weak tax-control processes.
Open demands shown only as a single net number without order-wise or year-wise detail.
Cross-border service fees, loans, guarantees, receivables or royalties without current agreements or defensible transfer-pricing support.
Tax provisions that remain unchanged despite new orders, appeals or settlements.
Management forecasts that assume tax losses, incentives or credits will be available without checking legal conditions and transaction impact.
A diligence data room that contains returns but omits notices, submissions, orders, challans or reconciliations needed to understand the underlying position.
How tax diligence connects with financial due diligence
Tax diligence should not operate in a silo. A tax issue can affect normalized EBITDA, cash flows, net debt/debt-like items, working capital or the purchase agreement. For that reason, transaction teams should connect findings with PGT’s related guides on Quality of Earnings in Financial Due Diligence, Net Debt in Financial Due Diligence and Working Capital Normalization in M&A. This integrated view helps prevent double counting—for example, treating the same tax payable once in working capital and again as a debt-like item.
FAQs
Is tax due diligence the same as a tax audit?
No. A tax audit or statutory compliance engagement has a defined legal or reporting purpose. Transaction tax due diligence is deal-specific: it identifies historical and recurring tax risks, tests the reliability of information, estimates potential economic exposure and helps parties decide how risks should be addressed in pricing and transaction documents.
How many years should tax due diligence cover?
There is no single universal period for every transaction. The scope should reflect open assessment periods, materiality, business history, deal size, known disputes and transaction objectives. Older years may remain relevant where litigation or proceedings are still open.
Should every tax demand reduce the purchase price?
Not automatically. A demand may be paid, stayed, disputed or subject to appeal. The transaction treatment should reflect the facts, probability and contractual allocation rather than mechanically deducting the face value of every notice.
Why is the 2026 direct-tax transition important in diligence?
Because income earned from 1 April 2026 onwards is governed by the Income-tax Act, 2025, while earlier periods and related proceedings can continue under the 1961 Act. A diligence schedule should clearly identify which framework governs each material issue.
Can tax diligence affect valuation?
Yes. Recurring tax costs can alter forecast cash flows, while identified historical liabilities can affect equity value or transaction protections. However, the treatment depends on the valuation model and purchase agreement, so the same item should not be counted twice.
Practical takeaway
For CFOs, promoters, investors and deal teams, effective tax due diligence in M&A India is not a compliance checklist exercise. It is a structured bridge between tax history, current law, financial reporting and deal economics. The best output is concise: what the issue is, how much may be at risk, how strong the evidence is, whether it is recurring, and what the transaction should do about it.
PGT & Associates supports businesses and transaction teams with financial and tax diligence, transaction analysis and related advisory work. Scope and conclusions depend on the facts, applicable law and engagement terms; no transaction, tax outcome or regulatory approval is guaranteed.
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