Tax Controversy 2025

A Global Overview of Tax Controversy in 2025

Uncertain times continue

Unpredictability introduced by Brexit, the COVID-19 pandemic and numerous wars (one after the other) seems to be continuing considering the tariffs imposed by the Trump administration, the retaliation by certain other states, and the risks and new disruptions on global supply chains. All these have had a clear impact on the global economy and financial markets, with global M&A activity slowing down. With this in mind, the climate is likely to be stressed and reflected in states’ budgets and the legal environment.

All these events and circumstances have a huge impact on budgets and taxes, and likely on further controversies in the years to come, given the additional stress put on the different players.

In order to combat the pandemic, governments supported individuals and companies in need with measures to postpone tax payments or embrace flexible approaches towards compliance with specific obligations. This is now over; however, public spending has since increased substantially, and global conflicts and the latest tariff wars are expected to increase pressure on budgets. Moreover, one cannot ignore that not long ago a new set of hard and soft law instruments was created to target certain behaviours. The situation is naturally different in each country, but some fear that new taxes will be created and, at the same time, predict that tax authorities will be inclined to become stricter and/or carry out more targeted audits. Nevertheless, the selection of taxpayers by tax authorities seems to be undisclosed in many countries; as the Belgium chapter asserts, the BEPS recommendations and the EU’s recent measures, as well as recent ECJ case law on abuse, are beginning to translate into tax disputes – and, in relation to audits, it makes clear that their (tax authorities) algorithms are a closely held secret. The Swedish chapter in this guide also calls our attention to all these factors.

More than ever, the management and control of tax risks are primary goals for both tax authorities and taxpayers. For the former, it is disastrous if the State is unable to collect the expected level of revenue. For the latter, tax is a significant cost for business, and an incorrect estimate can jeopardise a company’s level of profitability and damage its reputation, not to mention cause egregious disadvantages and losses. However, it is now almost certain that, in the short-term, debt and public expenses will increase while tax collection levels will drop due to the economic contraction.

It might be debatable whether taxes are historically a prime mover, as some have argued; however, one cannot ignore facts. The US experience after the 2008 crisis – when both tax authorities and multinational enterprises (MNEs) were in need of revenue, and neither was prepared to compromise easily – should be borne in mind. Currently, it seems that the IRS, as well as several other tax authorities, is focusing more of its attention on international tax issues and, more specifically, transfer pricing. The USA chapters in this guide call the reader’s attention to several other relevant areas, as well as to taxpayers that may be subject to a greater likelihood of audit. The French chapter informs us that the latest trends in French tax disputes mainly relate to international tax issues. A striking example is the increase in the number of transfer pricing cases and cases in which the French tax authorities challenge the economic substance of non-resident companies.

Owing to these risks, several authors, including in South European countries such as Greece or Portu-gal, direct special attention to the conclusion of advance pricing agreements (APAs). However, this is not a solution for certain countries (such as Brazil), mostly due to the inexistence of specific legislation that covers such possibility. Curiously, the Brazilian chapter does not hesitate to stress that tax uncertainty is a certainty in the Brazilian tax system, although one may find ways to mitigate risks.

Expected increase in tax litigation

Inevitably, no one can entirely anticipate and eliminate all adverse situations that might lead to disputes. Although disagreements may emerge suddenly and in relation to all types of taxes, the majority of chapters in this guide refer to the many international, complex and controversial substantive tax matters around the BEPS recommendations, including the adoption of Pillar Two and the legislation created thereafter, the Multilateral Instrument (MLI), digital taxation and the use of the general anti-abuse rule (GAAR) to challenge cross-border transactions. Some contributors cannot ascertain whether these have contributed to an increase in the level of tax controversies (such as Canada or Costa Rica). Many other authors, however, are already anticipating more litigation (Belgium, Portugal, Sweden). The same expectation exists with respect to the impact of the EU Mandatory Disclosure Directive (DAC 6), and many jurisdictions within the EU have mentioned this possibility.

Several chapters suggest that the amount of new legislation everywhere and the appearance of new and open concepts applied worldwide in the context of states struggling for financial resources create an expectation of increased litigation.

Although the EU member states have already implemented EU Directive 2022/2523, it remains to be seen whether domestic legislation implementing Pillar Two might result in an increase of litigation (and whether or not Pillar One will be adopted).

The recent new international instruments, such as the packages involving the collection of more data and exchange of information between tax authorities, DAC 6 and the MLI, are still expected to have a significant impact on how anti-abuse rules will be applied, though together will probably contribute to an increase in controversies and litigation.

The tax authorities of each jurisdiction might have different perspectives on and approaches to combating non-compliance with tax obligations or tax avoidance. Nevertheless, they are all undoubtedly better equipped and prepared, with substantially more information at their disposal about taxpayers as well as their own activity, and are much more integrated internationally, as mentioned by several chapters in this guide.

Curiously, this appraisal is not unanimous, with the Italian chapter admitting that, due to the incremental risks, taxpayers are likely to assume a more conservative approach in carrying out their business activities, which may contribute to a reduction in litigation over time.

Despite agreeing with this view towards taxpayers’ behaviour, tax authorities are placing increasing pressure on collecting taxes, and the borderlines and grey zones continue to subsist in many areas provoked by new legislation, open legal concepts, different interpretations, etc. Therefore, only time will tell whether or not litigation increases.

Audit strategy and the road ahead

The chapters in this guide note that taxpayers – even MNEs and high net worth individuals – are often caught in the crossfire created by the competition between states for capital and investment, and suffer from a changing and uncertain compliance landscape. As indicated in the USA chapter, this is a time of great uncertainty in the tax controversy realm and in many others. It is therefore extremely valuable to know how to anticipate, prepare for and manage possible audits or to verify whether it is possible to eliminate or mitigate tax risks, either before or during a specific controversy.

This guide presents an excellent overview of the tax controversies that are common and distinct in 31 very different jurisdictions. It provides a very interesting global analysis of trends, including:

• the origin and causes of tax controversies;
• the continuous efforts to combat tax avoidance and evasion;
• the means to mitigate and manage tax risks and to stay up-to-date with the best ways to settle cases; and
• the strategies to employ in the context of administrative or judicial litigation.

The reader will also be able to gather comparative information on all phases of tax litigation in each jurisdiction, in either domestic or cross-border disputes, and will be able to garner an idea of costs and statistics in the area of tax litigation, including the number of cases and the likelihood of a successful outcome for either the tax authorities or the taxpayers.

International tax authority co-operation

It is clear from all of this guide’s chapters that tax authorities are collecting more and more information on taxpayers and their businesses and cross-border activities, either through exchanges of information and mutual assistance, country-by-country (CbC) reports, the common reporting standard (CRS), or other mechanisms or groups (eg, the Joint International Taskforce on Shared Intelligence and Collaboration). The reporting obligations contained in DAC 6 will also soon be automatically exchanged in the EU.

Whether one is in Italy, China, Brazil or the USA, tax authorities now know more than in previous years. Given the specific circumstances, culture and approaches in each jurisdiction, there is no unanimity as to whether this will lead to an increase in tax controversies, though certain hints and assertions suggest that it will, at least in some countries. Above all, however, taxpayers may expect more prepared tax authorities, with more well-defined information and targets, meaning that scrutiny and perceived abuses and avoidance techniques will be systematically tackled. The USA chapters emphasise these aspects very clearly, and several others would appear to agree, stating that, with respect to IRS enforcement, the two principal trends that carried through 2024 were a better funded, growing and capable IRS and continued multilateral co-operation, and that the IRS has aggressively been pursuing areas of perceived abuse.

Litigation and tax authority approaches

According to the chapters in this guide, certain tax authorities are investing in minimising tax disputes, helping taxpayers effectively via direct contact, through tax rulings or through the use of alternative dispute resolution (ADR) mechanisms. It seems that this open approach is paying off, considering that, when litigation occurs, the tax authorities claim a higher success rate before the tax tribunals or higher courts (as emphasised by a few contributors).

In countries where the tax authorities seem more reluctant to invest in assisting taxpayers dealing with complex legislation and ambiguous matters, additional tax assessments have grown significantly, which also gives rise to an increase in the number of controversies. Unsurprisingly, this reflects negatively on how investors evaluate the “tax element” when researching the different aspects of doing business in that specific jurisdiction (the case of Brazil seems to be an example here). In these countries, taxpayers can usually prevail more often. Surprisingly, however, in the statistics presented by the Brazilian chapter concerning administrative tax cases, and according to the Federal Revenue Data, taxpayers lost BRL103 billion in 2023, which was three times more than in 2022.

The Chinese chapter emphasises the relevance of “smart tax (AI)” systems such as the fourth phase of the Golden Tax (including a comprehensive digital electronic invoice system), which can carry out comprehensive data management for enterprises and individual taxpayers. The conclusion is that tax authorities monitor taxpayers’ tax risks in a timely manner through intelligent analysis of big data.

Meanwhile, tax legislation and the tax authorities’ approach in certain other countries seem to occupy a middle ground between the types of patterns described above. Statistics regarding the success of tax authorities in litigation seem to be in line with this; as such, it is particularly interesting to analyse the statistics in each country and the reasons presented by the authors.

Efficient ADR mechanisms may also be very helpful in preventing/reducing disputes, or at least in resolving them quickly, as shown by the Portuguese domestic arbitration system. Administrative attitude and taxpayer culture still seem to be crucial elements; however, ADR mechanisms may not be sufficient without a willingness on the part of both the authorities and the taxpayers to work collaboratively, and with reasonable alacrity.

Criminal tax controversies

This guide also illustrates the way tensions may be avoided as they arise and how they may evolve from tax audits up to the higher tribunals, either through administrative and civil discussions where anti-avoidance rules (including transfer pricing) still play an important role, or in the context of tax evasion or fraud (involving, for example, dishonest conduct and false accounting) where such matters will usually be treated as crimes, and where the proceedings and the investigations are conceptually separate and evolve independently. The guide explains the differences, the possible interactions between tax assessments and tax infringements, and the possibilities to reduce fines and/or to initiate and conclude settlements. In some countries, there is an increased risk of criminal liability, not only for the taxpayers themselves but also for the so-called facilitators. Moreover, new situations start being scrutinised as crimes. The Israel chapter mentions that the management and control rule for determining the residency of a corporation was used as a basis for criminal proceedings, where the actual management and control over the corporation was exercised from a different country than the one reported.

In addition, it seems that there is a trend for more collaboration between tax and criminal bodies, including judicial authorities, through specialised joint investigation teams, as noted in the Belgium and Portuguese chapters, for example. The Belgium chapter stresses that, twice a year, the tax authorities and the College of the General Prosecutors hold a strategic meeting to determine priorities. Also, the French chapter stresses that the number of cases referred to the public prosecutor for tax fraud has increased over time, which has led to taxpayers increasingly engaging in ADR mechanisms in order to terminate criminal proceedings against them, often involving the payment of potentially substantial fines. This trend, and the same or different strategies, has also been pointed out in several other reports (Portugal), although some chapters also stress that it is very rare for tax controversy cases of sophisticated corporate taxpayers to develop into criminal cases (Japan). However, as the UK chapter reveals, there will be a rise in the number of HMRC investigations into tax fraud-related offences and associated prosecutions, as well as a crackdown on alleged tax avoidance in the next few years, and this is also not an isolated case.

Finally, a new criminal trend seems to be emerging involving many other persons aside from the taxpayers themselves. The Swiss chapter should be read attentively: the criminal liability of directors, advisers and controllers is increasingly being taken up by the tax authorities during audits, which leads to additional risks for the persons involved. To date, though, few cases illustrate this.

Litigation strategy

This guide takes the reader through different geographies and along various administrative and judicial routes, from the first to the final stages (that is, considering administrative hierarchical or judicial appeals), considering the deadlines, intricate proceedings and rules and principles that reveal how disputes may be settled in the most appropriate manner.

Despite the existence of completely different procedural rules and ways to settle tax disputes, there are several important common features that contribute to taxpayers’ best interests and that are stressed by the majority of authors in this guide. These include:

• the importance of being prepared before an audit has even started, and of being assisted by a legal adviser from the first hour;
• the need to be fully conversant regarding all the relevant facts around the potential controversy, and to evaluate the risks and associated contingencies in order to minimise them;
• supporting the facts and bolstering the substance of the case, disclosing documentation and engaging expert assistance, or any other necessary support;
• verifying whether the dispute may be narrowed, by either settling or abandoning any of the issues, but making wise use of all procedural and material rights; and
• the importance of an awareness of previous case law, even in civil law jurisdictions where precedent does not have the same influence as in common law systems – this importance increases with the need to know international jurisprudence from the ECJ or the ECHR, and to be aware of comparative jurisprudence or doctrine.

Naturally, in-depth analysis of a case, its facts and the applicable rules of law are crucial to mastering tailor-made strategies for individual cases, as this guide repeatedly emphasises. The reader will certainly understand that, in spite of globalisation and similar concepts/substantive tax issues (such as transfer pricing matters, hybrid mismatches, recharacterisation issues or cross-border disputes after BEPS) or procedural rules and principles, the way disputes may best be settled in each country is still part of the expertise and art of practitioners in the respective jurisdictions.

International issues

The different chapters in this guide also emphasise the use of domestic or international tools (such as the mutual agreement procedure) to solve cross-border disputes, indicating how they usually interact. Some of the chapters allude to the MLI, considering that this is already in force in several countries, and provide an idea of related crucial matters.

Naturally, the issue of state aid disputes involving taxes does not apply to all jurisdictions; however, within the EU it is a hot topic to which member states and taxpayers should pay great attention for its practical impact on sensitive matters (where exemptions and incentives could be withdrawn, and turnaround in the recovery of taxes and interest is a real possibility), as some of this guide’s EU chapters demonstrate.

It is also interesting to observe that application of the GAAR and specific anti-abuse rule (SAAR) in a treaty context have already been challenged in several court cases. However, the majority of chapters choose to stress confidence in their compatibility, as tax authorities and states have repeatedly shown (along with the OECD Model Tax Convention commentaries), suggesting that taxpayers should – if not must – adopt conservative approaches to exploiting double taxation treaty opportunities. The MLI also contributes to changing the situation, particularly considering the “saving clause” (Article 11).

The fight for income from international taxation ignites intense discussion, not only among taxpayers but also among different tax authorities and states. The appearance of so many new tools and weapons to combat tax avoidance allows us to predict that tax disputes will increase, unless great investment is made in assisting taxpayers on a daily basis and in creating ADR mechanisms. Ironically, it seems that, even while an avalanche of new measures has been created to combat taxpayers’ abuses (BEPS, DAC 6, etc), states have felt the need to create quick arbitration mechanisms to settle tax disputes between themselves (eg, the MLI and the EU Arbitration Directive).

Conclusion

Authors from several jurisdictions predict stricter audits and additional tax assessments in the near future, and possibly even more taxes. Once the Russia-Ukraine and Israel-Palestine conflicts recede (although predictions of their absolute conclusion are still pure speculation at this point) and the tariffs wars terminate, the authorities will have to consider the approach to “recovery”, given that states will want to preserve their business sectors for long-term economic growth. Clearly, given the current status quo, taxpayers should be more proactive in their internal audits and the analysis and management of their tax risks.

Considering that every move takes time and that the state of the art in each jurisdiction is at a different stage of development, the present guide is an excellent tool for professionals (tax lawyers, barristers and in-house lawyers, as well as company CFOs and members of their departments, tax consultants, judges or other professionals). It provides a compass with which to determine the right path forward when preparing and handling a tax audit or controversy, to assist either in managing a good settlement or, if this proves unworkable, in conducting a successful dispute.