A Greek tax appeals body has canceled a €16,641 tax assessment after concluding that a Monaco bank had mistakenly reported investment income through the international automatic exchange of financial information system, a case that illustrates both the strengths and the vulnerabilities of cross-border tax transparency.
The ruling, issued by Greece's Directorate for the Resolution of Tax Disputes(DED) under Decision No. 2733/2026, overturned an income tax reassessment and a related penalty imposed on a taxpayer for the 2018 tax year after authorities determined that the underlying information supplied through international reporting channels was incorrect.
The dispute began after Greece's tax administration received data through the automatic exchange of financial account information between jurisdictions, an international framework designed to help tax authorities identify undeclared offshore income. According to the information transmitted, the taxpayer had received €22,843.59 in interest income from a bank account in Monaco. Acting on those figures, the Athens Tax Audit Center revised the individual's tax return, adding the foreign interest income to his taxable earnings.
The consequences were significant. A tax return that had originally generated a refund of €11,158.65 was transformed into a tax liability of €16,641.12. The taxpayer was also assessed a €100 administrative penalty because the tax authority treated the reassessment as an amended income tax return.
The dispute
The taxpayer immediately challenged the assessment, arguing that the reported interest income did not belong to him. He explained that the Monaco account was jointly held with his father and submitted documentation from the bank stating that a technical error had affected the information it had reported to the tax authorities.
According to the bank's letter, the reporting error had been identified and the institution would work with Monaco's tax authorities to correct the information already transmitted to Greece through the automatic exchange system.
The taxpayer further argued that his father had already declared the relevant interest income by filing an amended tax return and had paid the tax due on those earnings, leaving no additional tax obligation for him.
During its review, the DED found that the Monaco bank had indeed corrected the information submitted through the international reporting network. The revised data showed that the interest associated with the joint account amounted to €5,559, rather than the €22,843.59 initially reported. The appeals authority also confirmed with the relevant Greek tax service that the corrected information had been successfully transmitted through the automatic exchange mechanism and now matched the bank's revised records.
The DED also verified that the taxpayer's father had filed an amended 2018 income tax return declaring the €5,559 in foreign interest income. On that basis, the authority concluded that the taxpayer had no outstanding tax liability arising from the account and that the original assessment had been based on inaccurate information.
The appeals body accepted the taxpayer's administrative appeal, canceled both the additional income tax assessment and the €100 penalty, and restored his original tax position for the 2018 tax year.


































