A Dutch acquirer signing a share purchase agreement for a target with subsidiaries in Luxembourg and Switzerland is not buying one company. It is buying a tax position in three jurisdictions at once, each with its own participation regime, withholding rules and filing deadlines. Cross-border M&A tax advisory is the work of making that position visible before signature and keeping it defensible long after closing.
How does an international tax advisory firm assist companies with cross-border mergers and acquisitions?
An international tax advisory firm works along the whole arc of a transaction rather than at a single point in it. WVT’s attorneys and tax advisors run tax due diligence on the target, design the acquisition and financing structure, translate the diligence findings into the warranties and indemnities of the purchase agreement, execute the notarial and registry steps at closing, and keep the structure compliant once the deal team has moved on. Sequence matters more than any individual step. A structure redesigned after the price has been agreed almost always costs more to fix than it would have cost to plan, which is why corporate tax services belong in the room from the first draft of the letter of intent.
Tax due diligence: establishing what the price should reflect
Tax due diligence is a search for liabilities that have not been assessed yet. The target’s filed returns are the starting point, not the answer. What surfaces in a cross-border file is usually one of a handful of things: historic transfer pricing positions that were never documented, a permanent establishment created quietly by staff working from another country, participation exemption claimed on holdings that may not qualify, or a ruling granted on facts that have since changed.
Each jurisdiction adds its own question. A Dutch target holding real estate brings transfer tax (overdrachtsbelasting) into the calculation, and whether the transaction is taxed at the share level depends on the composition of the target’s assets. A Luxembourg holding raises the question of whether its participations qualify under article 166 of the Luxembourg income tax law. Swiss cantonal rulings are granted on a stated set of facts, and a change of control is exactly the kind of change that puts their continued application in question.
The output is not a document for its own sake. Each finding is priced, then allocated: reflected in the purchase price, covered by a specific indemnity, or accepted. Our earlier piece on the pitfalls acquirers get wrong in international M&A tax planning sets out what happens when that allocation is skipped.
Structuring the acquisition: where the vehicle sits and how profits come home
The acquisition vehicle determines how cash moves afterwards. A Dutch holding company can receive qualifying dividends and capital gains free of corporate income tax under the participation exemption in article 13 of the Corporate Income Tax Act 1969; Luxembourg offers a comparable regime under article 166 LIR. Neither is automatic. Both depend on shareholding thresholds, on the subject-to-tax position of the subsidiary, and on the holding being more than a name on a register.
Financing is where plans most often narrow. Pushing acquisition debt down into the target’s jurisdiction looks efficient until the interest limitation rule from the Anti-Tax Avoidance Directive applies, implemented in the Netherlands as the earnings-stripping rule in article 15b of the same Act. Treaty access is the second constraint: the principal purpose test introduced through the OECD multilateral instrument denies treaty benefits where obtaining them was a main purpose of the arrangement, so substance in the holding jurisdiction has to be real and documented. Where the deal takes the form of a merger rather than a share purchase, the EU Merger Directive (2009/133/EC) can defer taxation on the reorganisation itself, subject to conditions each member state applies in its own way. The same principles are set out at group level in our guide to international tax structuring for cross-border groups.
In the documents: how tax risk lands in the purchase agreement
Diligence findings are worth little until they appear in the contract. Tax warranties cover the unknown; a specific tax indemnity covers the identified exposure, often backed by an escrow or a holdback until the relevant statute of limitation expires. Whether the parties use a locked box or completion accounts decides who carries pre-closing tax liabilities, and the drafting here is unforgiving: an indemnity that triggers only on a final assessment can leave the buyer funding years of procedure before it pays out.
One obligation is easy to miss in the rush to signing. A cross-border reorganisation can be a reportable arrangement under the EU mandatory disclosure rules, and the reporting window is 30 days from the trigger. WVT handles DAC6 reporting alongside the transaction rather than after it, because the deadline runs whether or not anyone on the deal team noticed.
Closing: deeds, registers and the steps that cannot be rushed
Civil law jurisdictions put a notary in the critical path. Shares in a Dutch BV transfer only by notarial deed executed before a civil-law notary, and a Luxembourg SARL follows a comparable route. Swiss mergers, demergers and conversions run under the Merger Act, with registry filings that set the legal effective date. None of this is a formality: the deed is the moment the transaction legally occurs, and a missing power of attorney, an unlegalised corporate document or an unresolved UBO filing can push a signing by a week.
Having the notarial services inside the same mandate as the tax work removes the handoff where most closing delays originate. The tax structure, the deeds giving effect to it and the register entries proving it then describe the same transaction.
After closing: integration, reporting and defending the structure
The structure now has to survive scrutiny. For groups above the EUR 750 million consolidated revenue threshold, Pillar Two changes how the post-deal effective tax rate is calculated and adds a reporting layer that an acquisition can reshape mid-year. Below that threshold the questions are different but no less practical: which acquired entities can be merged away, which must stay for licensing or treaty reasons, where board meetings are held, and who signs what.
This is where an adviser who was present during diligence earns their place. The person who knows why the Luxembourg holding was chosen is the person best placed to explain it to an inspector three years later.
Choosing a cross-border M&A tax adviser
Firms describe themselves in similar terms, so the useful questions are narrow ones. Ask which jurisdictions the firm covers with its own qualified people rather than through a referral network, since every handoff between advisers is a place where a deadline or an assumption goes missing. Ask whether legal, notarial and tax work sit under one mandate or three, and who holds the overall timetable if they do not.
Then test for continuity. The partner in the pitch is not always the person who writes the report, and an adviser who disappears at closing leaves the post-closing filings to a team that has to reconstruct the reasoning. Ask directly who will be available in year two, and whether the firm will stand behind the structure if a tax authority challenges it.
Speed is the last criterion, and the one most often discovered too late. Deals move in days, and an adviser who needs a week to turn around a structure memorandum will shape the transaction by their absence. For a CFO or in-house counsel running a competitive process, response time is a substantive quality, not a service detail.
One practical rule outranks the rest: involve tax advisers before the letter of intent is signed. Once the structure is fixed in a signed LOI, the options that cost nothing in week one acquire a price, and renegotiating them costs goodwill that the integration phase will need.
Frequently asked questions
How does an international tax advisory firm assist companies with cross-border mergers and acquisitions?
Support runs across the full transaction: tax due diligence on the target, design of the acquisition and financing structure, drafting the tax warranties and indemnities in the purchase agreement, notarial execution and registry filings at closing, and post-closing compliance and integration. The practical value lies in one team holding all of it, so the structure that was designed is the structure that is actually documented and filed.
How do I select the right tax adviser for a cross-border merger?
Look at jurisdictional coverage with in-house qualified people rather than referrals, at whether legal, notarial and tax work sit under a single mandate, and at continuity between the diligence team and the post-closing team. Response time matters as much as technical depth in a competitive process. Asking who will defend the structure in an audit three years from now separates firms quickly.
Why did our tax liability rise after the acquisition?
Common causes are a holding company that fails a substance or principal purpose test, so treaty withholding relief is denied; acquisition debt caught by the ATAD interest limitation rules; or a pre-closing exposure that diligence identified but the agreement never allocated. Each is traceable to a decision taken before signing, which is why structuring work belongs ahead of price agreement rather than after it.
When should tax advisers be brought into the deal?
Before the letter of intent, ideally. The LOI usually fixes the transaction form, the acquiring entity and sometimes the financing, and each of those is a tax decision disguised as a commercial one. Advisers brought in at the SPA stage can still mitigate exposure through indemnities, but the cheaper options, such as choosing a different acquisition vehicle, have already closed.
Does Pillar Two affect mid-market cross-border deals?
Direct application is limited to groups above EUR 750 million in consolidated revenue, so most mid-market transactions fall outside it. Indirect relevance is wider: a target that is acquired by an in-scope group enters that group’s calculation, and buyers inside scope increasingly ask for Pillar Two data during diligence. Sellers who can produce that data move faster through the process.
