Case law confirms application of accountants’ and tax advisers’ professional privilege during tax audits

In a ruling of 24 June 2025 (No. 2024/AR/961), the Court of Appeal of Ghent (“the court”) ruled that the tax authorities do not have an unlimited right to examine the correspondence between a taxpayer and their accountant. The court confirmed that such correspondence is privileged, and that the tax authorities may only audit the taxpayer’s data (e.g., email inboxes) after the competent disciplinary body (the Institute for Tax Advisors and Accountants (ITAA)) has filtered the privileged correspondence.

Legal framework

Article 120 of the Law of 17 March 2019 concerning the profession of tax advisers and accountants confirms that (certified) tax advisers and accountants must abide by the rules of professional privilege. They are prohibited by law from disclosing the “secrets” entrusted to them by their clients. 

The rules of professional privilege apply to certified tax advisers and accountants (including legal entities). Additionally, the law extends these rules to trainees, as well as to those for whom the certified tax advisers and accountants are responsible (i.e., their employees), and to individuals who practice the profession temporarily and occasionally. Everyone who practices the profession of tax adviser or accountant should abide by the rules of professional privilege.

It is clear that these rules apply to tax audits in the hands of tax advisers and accountants, which implies that they themselves cannot share privileged information on their clients upon the request of the tax authorities (article 334 of the Income Tax Code and article 53quinquies of the VAT Code). 

However, in practice Deloitte (Legal) Belgium sees issues from the other side of tax audits, with the tax authorities often challenging the privileged nature of correspondence with tax advisers and accountants when auditing their clients (i.e., the taxpayers).

Privileged correspondence must be respected by the tax authorities

In its 24 June 2025 judgment, the court had to rule on the extent to which the tax authorities could access the taxpayer’s data, including the correspondence between the taxpayer and, among others, their accountant.

The court acknowledged that a taxpayer is not covered by the law on professional privilege. However, the fact that the taxpayer is not personally required to observe the rules of professional privilege does not deprive the taxpayer of the right to invoke privilege regarding data that does originate from a relationship subject to professional privilege.

Furthermore, the court confirmed that professional privilege of accountants (and thus also tax advisers) must be afforded the same protection as the legal professional privilege of lawyers. Hence, while the tax authorities are allowed to audit the data of a taxpayer, such an audit cannot include privileged correspondence, whether it be from a lawyer, tax adviser, accountant, medical professional, etc.

When the tax authorities nonetheless obtain such data from the taxpayer, for instance following a mass data download (emails, correspondence, etc.), the privileged data must be filtered by the competent disciplinary body (the ITAA for tax advisers and accountants) before it can be consulted by the tax authorities. 

Key takeaways

The judgment of the court provides welcome confirmation of the privileged nature of correspondence between a taxpayer and their tax adviser and/or accountant. 

Whenever a taxpayer is subject to a tax audit (especially when faced with a “dawn raid”), it is important for both the taxpayer and their advisers to identify the data protected by the tax adviser’s and the accountant’s professional privilege as soon as possible and to ensure that the tax authorities do not gain access to such data without the necessary safeguards being respected.

As a best practice, it is advisable to explicitly label communications as confidential to facilitate a potential review by the disciplinary authority and to minimise disputes in this respect.