The next frontier of tax transparency: from pillar two to digital platforms

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The next frontier of tax transparency: from pillar two to digital platforms

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Teresa Teixeira Mota of VdA analyses how evolving tax transparency frameworks are reshaping tax enforcement and dispute resolution in Portugal

For more than a decade, international tax policy has pursued a common objective: increasing transparency. What began with automatic exchange of financial account information has evolved into extensive reporting obligations covering multinational enterprises (MNEs), digital platforms, and individual taxpayers. Yet transparency is no longer an end in itself. It has become the primary mechanism through which tax authorities identify risks and select taxpayers for audit. The question is no longer whether taxpayers will be subject to scrutiny but how they manage the consequences of operating within an information-rich enforcement environment.

Portugal reflects this broader trend. Alongside the OECD’s pillar two rules, implemented through the Regime do Imposto Mínimo Global (RIMG), the Portuguese Tax and Customs Authority is gaining access to unprecedented volumes of information concerning income generated through digital platforms under DAC7. These initiatives share a common purpose: enabling more effective tax enforcement through data-driven compliance. As a result, the next wave of tax disputes will focus less on uncovering hidden income and more on interpreting increasingly complex tax rules.

Pillar two and MNE groups: a new reporting and enforcement paradigm

The transposition of Council Directive (EU) 2022/2523 through Law No. 41/2024, approving the RIMG, is now well established. Rather than revisiting the mechanics of the income inclusion rule, the undertaxed profits rule, and the qualified domestic minimum top-up tax, the focus should shift to what these rules mean in practice: not merely additional tax calculations, but a fundamentally different relationship between MNE groups and tax authorities.

The GloBE Information Return (GIR) exemplifies this shift. Authorities now receive granular, standardised data on group structures, effective tax rates, and jurisdictional allocations without issuing information requests. Combined with automatic exchange mechanisms, this transforms tax audits from investigative exercises into verification processes. The Portuguese Tax and Customs Authority will increasingly arrive at audits with a detailed picture already formed, expecting taxpayers to explain apparent discrepancies.

Early controversies under pillar two are unlikely to concern whether top-up tax is payable in principle. Instead, they will turn on interpretative questions the OECD Administrative Guidance does not fully resolve:

  • The boundaries of transitional safe harbours;

  • Timing differences between GloBE and domestic rules; and

  • The evidential weight of information exchanged between jurisdictions.

Portuguese courts will face novel questions about applying technical international standards within a constitutional framework designed for traditional tax disputes.

Digital platforms and the visibility of individual income: DAC7 in focus

At the same time, tax transparency is also expanding beyond large corporate groups. Portugal implemented Council Directive (EU) 2021/514 (DAC7) through Law No. 36/2023, establishing reporting obligations for platform operators covering immovable property rental, personal services, the sale of goods, and transport rental, enabling the tax authority to receive information on income earned through digital platforms.

Content creators and influencers illustrate the practical consequences. Influencer earnings combine multiple revenue streams: advertising payments, sponsorship fees, affiliate commissions, subscriptions, and platform monetisation. Each stream may have different tax treatment depending on whether the activity is occasional or continuous, and whether the payer is domestic or foreign. The tax authority now has access to much of this information automatically, but the legal framework for characterising such income remains underdeveloped. Disputes will increasingly concern not whether income exists but how it should be classified.

Emerging controversies include non-cash remuneration (complimentary products, travel, or accommodation in exchange for promotion), which raises valuation questions Portuguese tax law does not directly address. The deductibility of expenses associated with content creation – including equipment, travel, home office costs, and production services – depends on distinctions between personal and business use that are inherently fact intensive. VAT treatment of cross-border digital services involves complex place-of-supply rules many creators are not well placed to navigate.

The cross-border dimension compounds these challenges. Many influencers derive income from platforms in jurisdictions with which Portugal has no tax treaty. Double tax treaties were not designed with the creator economy in mind, and Portuguese courts have yet to develop substantial case law. Greater transparency surfaces these ambiguities rather than resolving them.

The convergence of tax transparency regimes

What distinguishes the current moment is the integration of reporting frameworks. The Portuguese Tax and Customs Authority now cross-references Common Reporting Standard data, DAC6 disclosures, DAC7 reports, and pillar two information through sophisticated risk assessment algorithms. A DAC7 report revealing platform income may be matched against a personal income tax return; a GIR disclosure may prompt questions about transfer pricing arrangements previously reported under DAC6. Inconsistencies that might have remained undetected in siloed systems now surface automatically.

The practical implication is clear: the pre-litigation stage has become the decisive phase of tax controversy management. Managing tax risk requires consistency across multiple disclosures, anticipating how information reported in one context may be interpreted in another. Finance, tax, and operational teams must communicate effectively, and advisers must take a holistic view of compliance with an eye to potential disputes.

Tax litigation in Portugal will increasingly concern the interpretation of information authorities already possess, not its discovery. Courts will resolve disputes where the factual record is largely uncontested but legal consequences remain uncertain. Success will depend on anticipating enforcement priorities, identifying interpretative ambiguities before they crystallise into assessments, and engaging constructively with authorities early. The taxpayers best positioned to navigate this landscape will treat transparency not as a compliance burden but as a strategic discipline.

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