International Tax Attorneys | McDermott Tax Controversy Lawyers

Non-US Tax Controversy


Outside of the United States, our global team delivers detailed advice and on-the-ground support for tax audits, dispute prevention, dispute resolution and litigation.


Drawing on years of experience working with clients from individuals to multinational companies, our team can help you successfully navigate any audit or inquiry from the French tax authorities, along with litigation in the French courts.

For private clients, we advise on disputes in relation to management packages, along with trust and estate planning. On the corporate side, we are skilled at handling transactional and cross-border tax matters like business restructuring, transfer pricing and permanent establishment disputes. We assist you during the pre-litigation stages, from tax audits to mutual agreement procedures—and ultimately, if the tax authorities refuse to reduce or abandon tax adjustments through negotiation, we defend your interests with tax litigation and represent you in court.

As a global team with an international footprint, we take a collaborative approach to any tax litigation that could have cross-border repercussions. We develop and coordinate your defense in close partnership with our highly regarded international colleagues, taking care to ensure from the beginning that our arguments will work seamlessly across jurisdictions.

We also handle disputes and litigation related to tax evasion and search and seizure operations, especially for multinational companies that might have an undisclosed permanent establishment in France. In France, audits are increasingly leading to a hybrid of tax and criminal proceedings, and we work closely with our white-collar colleagues on efficient cross-practice strategies and defense options to help you achieve a favorable outcome.


We can help you navigate the full span of tax controversies in Italy. Among other areas, our team has skill and experience in negotiating deals with the tax authorities, pursuing mutual agreement procedures for international tax dispute settlements and litigating matters both in the lower courts and in front of the Supreme Court.

With an excellent track record in handling a variety of disputes, we can steer you through any controversy from start to finish, setting long-term strategy with your end objective in mind. Drawing on our experience and familiarity with the Italian tax authorities and courts, we assess risks, weigh pros and cons and determine your chances of success in various scenarios to present you with the optimal solution for your tax controversy.

Our team keeps close watch on new developments in alternative dispute resolutions and international disputes, such as the anti-tax avoidance EU directives, to help you plan. We frequently take on cross-border and international tax litigation for large corporations and multinational companies, particularly regarding the application of the EU directives and tax treaties. We are also well-placed to handle transfer pricing issues, as well as challenges on reorganizations, tax restructurings and the relevant application of the anti-abuse rules on those transactions.

United Kingdom

With clients ranging from high net worth individuals to alternative investment funds to large multinational corporations across a range of industry sectors, our UK tax team has the experience and skill to advise on tax planning matters and to help you implement a long-term strategy to future-proof your business against the threat of tax disputes and litigation. Should you face an enquiry from HM Revenue & Customs (HMRC), our team can help you negotiate with HMRC with a view to settlement and closure. If you do face litigation, we draw on longstanding relationships with trusted barristers to represent you before the tribunals.

As a team of UK tax lawyers, we are well positioned to provide an independent perspective that can surface new solutions to benefit your business. In doing so, we work alongside your existing advisors, such as accounting firms, to provide legal analysis and additional support on UK tax matters. For example, we often work with the auditors of multinational corporate clients by providing legal opinions on uncertain tax positions, or where the tax outcome of a particular transaction is unclear. We also regularly seek non-statutory clearances on a range of UK tax matters on behalf of our clients where appropriate.

To help your company handle post-merger integration, minimize the risk of challenges from revenue tax authorities, defend against criminal liability and address other potential issues, we collaborate with top-ranked colleagues across practices in our offices around the globe.


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