Court of Appeal of Ghent Clarifies Boundaries of Tax Investigations and Data Requests

On 24 June 2025, the Court of Appeal of Ghent delivered a comprehensive judgement that further delineates the principles governing the Belgian tax authorities’ rights to request information and the corresponding obligations of taxpayers. This decision offers valuable guidance on the scope and limitations of tax investigations, particularly in the context of digital data and mailboxes used for both private and business purposes.

The tax authorities have extensive powers to conduct tax audits, including the authority to inspect digitally stored records and electronic mailboxes utilized for professional or business purposes. The taxpayer is required to cooperate or to provide such data in a legible and readily comprehensible format upon request, whereby the mere mixing of private and business emails does not diminish the taxpayer’s duty to cooperate with an investigation.

Nevertheless, any data requested or copied by the authorities must be collected for specific, legitimate, and explicitly described purposes. In this regard, the data must be adequate, relevant, and limited to what is strictly necessary for those purposes. The Court reiterated its longstanding position that so-called “fishing expeditions” – searches for incriminating data without concrete cause – are not permitted. 

Notably, since 2022 the tax administration has been empowered to request the court to impose a penalty on taxpayers who obstruct tax investigations without legitimate reason. Under this procedure, which is handled and initiated as in interlocutory proceedings (kort geding), the (fiscal) judge determines both the frequency and amount of the penalty, which only takes effect after formal notification to the taxpayer. Crucially, taxpayers retain the right to defend themselves by demonstrating a legitimate reason for non-cooperation.

Building on these principles, the Court confirmed that the tax administration is entitled, in the first instance, to determine which mailboxes and digital data are relevant for tax purposes. Only by unsealing the data can the administration properly assess its relevance. Consequently, taxpayers cannot rely on the mixed nature of their mailboxes to limit the administration’s investigative powers. However, the Court was careful to stress that the administration must act “with the greatest possible caution” when handling private correspondence.

The Court stressed that the tax administration must have concrete indications of relevance before requesting access to broad datasets. In casu, the administration had specific indications of fraud and had communicated these to the taxpayer, thereby justifying the broad data request. The Court made it clear that, in the absence of such indications, the administration cannot randomly search large pools of data for potentially relevant information.

In addition, the Court recommended that the administration use precisely selected search terms tailored to the focus of the investigation when filtering released data. This approach, the Court noted, mirrors the process that would occur if the search were conducted at the taxpayer’s premises. The Court indicated that this method is particularly appropriate in cases not involving tax fraud.

Furthermore, the Court reaffirmed that correspondence between taxpayers and professionals bound by professional secrecy (such as lawyers, accountants, and notaries) is protected and cannot be accessed by the tax authorities. This position is consistent with previous case law (see the Court’s judgement of 25 June 2024), although it is noteworthy that the Belgian State has appealed this decision, and the matter is currently pending before the Supreme Court (“Hof van Cassatie”).

Taken together, this judgement provides helpful clarification for both taxpayers and the tax administration. While the tax authorities retain significant investigative powers, these powers are not without limits. The Court’s guidance on the use of search terms and the requirement for concrete indications of relevance will help ensure that taxpayers’ rights are respected, especially with regard to private correspondence and professional secrecy.

For further information or tailored advice, please contact your KPMG tax advisor.

This newsflash is for information purposes only and does not constitute legal advice.