Tax Warranties, Indemnities and W&I Insurance: Allocating Tax Risk in M&A

In cross-border M&A transactions, the allocation of tax risk between buyer and seller is one of the most consequential – and frequently contested – elements of any deal. Tax warranties, tax indemnities and warranty and indemnity (W&I) insurance each serve distinct functions in managing that risk, and the choice between them, or the combination of them, depends on the target's tax history, the governing law of the transaction, the appetite of the parties, and the availability of insurance capacity in the relevant market. A clear-eyed understanding of how these instruments interact is essential before negotiations reach an advanced stage.

Why Tax Risk Demands Separate Treatment in M&A

Tax liabilities occupy an unusual position in the landscape of M&A risk. Unlike commercial disputes, which tend to be visible during due diligence, tax exposures can remain latent for years: a transfer pricing arrangement that the target considered arm's-length may be re-characterised on audit; a cross-border financing structure may fall foul of anti-avoidance rules enacted after the transaction closes; treaty positions taken in good faith may be challenged by a revenue authority operating under revised administrative guidance. The buyer acquires not only the target's assets and business but also – unless the structure is an asset deal with clean carve-outs – its entire tax history.

This is why experienced practitioners invariably treat tax risk separately from general commercial warranties. The time horizon for tax claims is longer, the technical complexity is greater, and the interaction between domestic law and international frameworks – tax treaty networks, OECD transfer pricing guidelines, BEPS minimum standards – creates layers of uncertainty that a standard warranty regime is ill-suited to address.

Tax Warranties: Scope, Limitations and Drafting Considerations

A tax warranty is a contractual representation by the seller as to the tax position of the target at a given point in time. In a well-drafted sale and purchase agreement (SPA), the tax warranty schedule will address: the accuracy and completeness of tax returns filed; the absence of material open disputes or pending tax audits; compliance with transfer pricing documentation obligations; the availability and accuracy of any tax reliefs, losses or credits that are reflected in the target's accounts; and the absence of transactions that could attract challenge under anti-avoidance rules applicable in the target's jurisdiction.

Tax warranties are valuable because they force disclosure: a seller who wishes to qualify a warranty must disclose the underlying fact, and that disclosure itself becomes part of the negotiated record. If the seller discloses a known tax audit, the buyer can price the risk or walk away; if the seller fails to disclose and the warranty proves false, the buyer has a contractual remedy. However, warranties have structural limitations that practitioners must understand:

• Limitation periods: SPA limitation periods for warranty claims are almost always shorter than the statutory period during which a tax authority may open an inquiry. A buyer relying solely on warranties may find that the warranty claim window has closed before the underlying tax exposure crystallises.
• Financial exposure caps: General warranty packages typically include aggregate liability caps set as a percentage of deal value. A tax exposure that arises years after closing may exceed or approach that cap, leaving the buyer undercompensated.
• Knowledge qualifiers: Sellers frequently seek to qualify warranties by reference to their awareness. In a complex group structure, determining what the seller "knew" about a tax position taken by a subsidiary can become a source of protracted dispute.
• Quantification difficulties: Even where a warranty claim succeeds in principle, quantifying the buyer's loss requires establishing what price would have been agreed had the warranty been accurate – a counterfactual exercise that courts and arbitral tribunals approach differently across jurisdictions.

If your transaction involves a target with operations in multiple jurisdictions or a history of aggressive tax structuring, our team would be pleased to discuss the specific warranty regime best suited to your circumstances. You are welcome to write to us at info@ferrazwhitmore.com or visit our contacts page.

Tax Indemnities: A Sharper Instrument for Known and Quantifiable Risk

Where a specific tax risk has been identified – whether through due diligence, seller disclosure, or the buyer's own analysis – a tax indemnity provides a more targeted form of protection than a general warranty. Under a tax indemnity, the seller agrees to pay to the buyer (or, in some structures, directly to the target) an amount equal to any tax liability that arises from a defined set of facts, events or periods. The indemnity operates on a pound-for-pound basis: there is no need to establish a reduction in the consideration that a hypothetical buyer would have paid. This makes the indemnity a more reliable remedy where the exposure is real but its quantum is uncertain.

The key drafting questions for a tax indemnity include:

• Scope of the indemnified period: Most tax indemnities cover pre-closing tax periods. The boundary between pre- and post-closing periods requires careful definition, particularly where the target operates on a non-calendar tax year or where a transaction straddles a fiscal year-end.
• Conduct of disputes: The seller, as the party bearing the financial risk, will typically seek control over – or at minimum meaningful participation in – the conduct of any tax audit or litigation relating to the indemnified period. The buyer, as the entity in which the target now sits, will be resistant to ceding operational control. Balancing these competing interests requires carefully drafted "tax conduct" provisions specifying notification obligations, cooperation requirements, and decision-making rights.
• Grossing-up and double recovery: Where an indemnity payment itself gives rise to a tax charge in the buyer's hands, the parties must agree whether the indemnity is to be grossed up. Similarly, where the buyer or target recovers the same loss from a third party (for example, a tax refund or a recovery under an insurance policy), clawback mechanics must be addressed to avoid double recovery.
• Tax treaty and transfer pricing positions: An indemnity that covers transfer pricing adjustments requires particular care. The seller may have taken a position on intercompany pricing that the buyer considers defensible; the buyer may take a more conservative view. If the parties disagree on the defensibility of the position, the conduct-of-disputes mechanism becomes critical.

In transactions involving targets with significant cross-border operations, the interaction between the tax indemnity and the target's broader tax risk management framework – including any advance pricing agreements, rulings, or cooperative compliance arrangements – deserves close attention. Our analysis of tax control frameworks and cooperative compliance, available at this link, sets out the relevant considerations in greater detail.

Warranty and Indemnity Insurance: Market Dynamics and Practical Function

W&I insurance has become a mainstream feature of M&A transactions in Europe, North America and a growing number of emerging markets. In its most common form, a buyer-side W&I policy allows the buyer to claim directly against an insurer for losses arising from a breach of warranty, without needing to pursue the seller. This has significant commercial implications: it de-risks the seller's post-closing exposure, facilitates clean exits (particularly in private equity contexts where the selling fund may be in the process of winding down), and – critically – removes or reduces the need for escrow arrangements that would otherwise tie up a portion of the consideration.

The tax dimension of W&I insurance is, however, considerably more nuanced than the general warranty coverage. Insurers routinely exclude from standard W&I policies a defined set of tax risks, including:

• Transfer pricing exposures, particularly where the target's intercompany pricing has not been benchmarked by contemporaneous documentation;
• Known tax disputes disclosed in the data room or in the seller's disclosure letter;
• Certain positions taken under anti-avoidance rules, especially where the transaction itself may have a tax avoidance purpose or effect;
• Tax treaty positions that are subject to challenge under the principal purpose test or similar provisions derived from the OECD's BEPS framework;
• Deferred tax assets whose recoverability depends on future profitability assumptions;
• Matters that were specifically identified as material tax risks in the due diligence report but not fully analysed.

Where a significant tax risk falls outside the scope of a W&I policy, the parties face a choice: negotiate a specific tax indemnity from the seller, obtain a stand-alone tax liability insurance policy (available in the London and US markets for specific identified risks), or price the risk into the consideration. Each approach has different implications for the transaction's economics and for the allocation of ongoing risk management responsibilities.

Stand-Alone Tax Insurance: A Complement, Not a Substitute

Stand-alone tax insurance – sometimes called tax liability insurance or tax risk insurance – addresses a specific, identified tax position rather than the full spectrum of warranty risk. It is typically used where a legal opinion supports the position taken but the risk of a contrary ruling by a tax authority cannot be excluded. Common use cases include: novel or untested treaty interpretations; the application of exemptions under domestic anti-avoidance legislation; the characterisation of a transaction for stamp duty or transfer tax purposes; and the deductibility of financing costs under interest limitation rules.

The underwriting process for stand-alone tax insurance is detailed and requires the insurer to form a view on the legal merits of the position. The insurer will typically require a legal opinion from qualified counsel in the relevant jurisdiction, access to supporting documentation, and disclosure of all communications with the relevant tax authority. Premium levels and coverage limits are individually negotiated and depend on the nature of the risk, the quality of the legal support, and conditions in the insurance market at the time of placement.

For transactions with a cross-border dimension – for example, where the target's tax structuring includes holding structures in multiple jurisdictions – stand-alone insurance can provide a degree of certainty that is otherwise difficult to obtain through contractual mechanisms alone. Our experience in advising on cross-border structures, including those with exposure in Eastern European markets, may be relevant; further information on our tax structuring practice in Ukraine is available at this page.

Interaction Between the Three Instruments: Strategic Sequencing

In practice, the most sophisticated transactions use tax warranties, tax indemnities and W&I insurance as complementary rather than competing instruments. A typical allocation logic might proceed as follows:

• General tax warranty coverage is obtained through the W&I policy, removing the need for the seller to retain meaningful post-closing liability for unknown tax risks;
• Specific identified risks that are excluded from the W&I policy – for example, a transfer pricing exposure flagged in due diligence – are addressed through a seller indemnity, with appropriate conduct-of-disputes protections;
• Novel or borderline positions where the merits are strong but the outcome is uncertain are covered through stand-alone tax insurance, providing the buyer with a funded remedy without requiring the seller to remain exposed.

The sequencing matters as much as the structure. Due diligence must be thorough enough to distinguish between unknown risks (which may be insurable under a W&I policy), known risks with uncertain quantum (which are typically indemnified), and known risks with defensible positions (which may be insurable under a stand-alone policy). Conflating these categories in negotiation leads to poorly drafted SPA provisions and gaps in coverage that only become apparent when a revenue authority issues an assessment.

Cross-Border Complexity: Anti-Avoidance, Transfer Pricing and Treaty Risk

For international transactions, the layers of tax risk multiply significantly. A target that has operated a centralised treasury function, an IP holding structure, or a cross-border financing arrangement will typically have taken positions on transfer pricing, treaty entitlement, and the application of domestic anti-avoidance rules that reflect the law as it stood – and as it was administered – at the time those arrangements were put in place. The buyer must assess not only whether those positions were defensible when taken but also whether they remain defensible under the law as it now stands.

Several developments in the international tax environment increase the relevance of this analysis:

• The OECD/G20 BEPS project has resulted in significant changes to treaty anti-abuse provisions, transfer pricing documentation requirements, and the treatment of hybrid instruments and entities. Targets that structured transactions prior to the widespread implementation of BEPS measures may hold legacy positions that are now vulnerable.
• Domestic anti-avoidance rules have been strengthened in many jurisdictions, and tax authorities have become more willing to apply general anti-avoidance provisions to structures that would previously have been considered straightforward. A tax audit of a pre-closing period may be conducted under a more aggressive interpretation of the law than applied when the arrangement was entered into.
• Transfer pricing disputes, by their nature, involve two or more jurisdictions. A successful challenge by one tax authority may, depending on available treaty mechanisms, lead to a correlative adjustment claim in the counterparty jurisdiction – but those mechanisms are procedurally complex and the outcome is not certain. The buyer must consider whether the indemnity or insurance coverage it has obtained addresses not only the primary assessment but also the risk of double taxation if a corresponding adjustment is not granted.
• The substance requirements applicable to holding structures and special purpose vehicles have tightened in many jurisdictions. A structure that relied on a treaty to exempt dividends or gains from withholding tax may face challenge if the relevant entity lacks sufficient economic substance.

Understanding how these issues interact across the specific jurisdictions involved in a transaction requires both technical tax analysis and a working knowledge of the relevant treaty network. Ferraz & Whitmore's corporate law practice has experience advising on multi-jurisdictional structures where these considerations arise; further details are available at our corporate law page.

Practical Due Diligence: Building the Risk Map

Effective allocation of tax risk in M&A starts well before the SPA is drafted. Due diligence must be designed to produce a risk map that distinguishes between categories of exposure, assigns a probability and quantum range to each, and identifies which instrument – warranty, indemnity or insurance – is appropriate for each identified risk. That risk map then drives both the negotiation of the contractual protections and the approach to the insurance market.

In practice, this means that the tax due diligence workstream must go beyond verifying the accuracy of tax returns and should include: a review of transfer pricing documentation and the robustness of the target's intercompany pricing methodology; an assessment of treaty positions taken in cross-border structures; a review of any prior tax audits and their outcomes; an analysis of any tax rulings or advance pricing agreements in place; and a specific review of any post-BEPS implementation changes in the target's jurisdictions of operation that may affect pre-existing structures.

Where due diligence is conducted under time pressure – as is frequently the case in competitive auction processes – the risk is that material exposures are identified too late to be properly addressed in the transaction documents. Early engagement of specialist tax counsel, with clear instructions on the scope and priority of the due diligence exercise, materially reduces that risk.

Outlook: Evolving Standards and Market Practice

The market for W&I insurance has matured significantly over the past decade, but it continues to evolve in response to changes in the broader tax environment. Insurers have become more sophisticated in their underwriting of tax risk, but have also become more selective: in markets where tax authorities are more active or where anti-avoidance legislation is less predictable, coverage may be narrower or premiums higher. The growth of Pillar Two – the OECD's global minimum tax framework – has introduced a new layer of potential liability for multinational groups, and the treatment of Pillar Two exposures under W&I policies is still developing.

Parties to M&A transactions should expect that the negotiation of tax risk allocation will continue to increase in complexity as the international tax environment evolves. A robust approach – combining thorough due diligence, carefully drafted contractual protections, and appropriate use of the insurance market – remains the most reliable means of managing that complexity.

If you are currently structuring or advising on a transaction that raises questions about the allocation of tax risk, we invite you to reach out to our team. You can contact us at info@ferrazwhitmore.com or through our contacts page to discuss how we may be able to assist.

Disclaimer: This publication is provided for informational purposes only and does not constitute legal advice. The information herein should not be relied upon as a substitute for professional legal counsel tailored to your specific circumstances. Ferraz & Whitmore assumes no liability for actions taken or not taken based on the contents of this material. For advice regarding your particular situation, please contact info@ferrazwhitmore.com.