Tax Administration Law amended: much higher fines and a new default-interest formula
TLDR
- Law adopted 9 July 2026, published in Off. Gazette 104/26 of 17 July 2026, in force since 18 July 2026.
- Fines for legal entities: from €1,000–15,000 to €4,000–40,000; for the responsible person: from €100–1,000 to €400–4,000.
- Fines for entrepreneurs (Art. 105a): from €500–6,000 to €1,000–12,000; lower-tier range from €100–1,000 to €200–4,000.
- Default interest is no longer a flat 0.03% per day — it is now the ECB base rate plus 3 percentage points per year, set and published by the Tax Administration every six months.
- New reporting duties are introduced (cross-border arrangements, crypto-asset service providers, platform operators) aligned with EU directives, as part of preparing for automatic information exchange with EU tax authorities.
On 9 July 2026 Montenegro's Parliament adopted the Law on Amendments to the Law on Tax Administration. It was published in the Official Gazette of Montenegro No. 104/26 of 17 July 2026 and entered into force the next day, 18 July 2026 — immediately, with no delay until EU accession.
The most concrete change for all taxpayers is a substantial increase in misdemeanor fines. For legal entities, the range for the most serious violations (failure to report, late filing, and similar) rose from €1,000–15,000 to €4,000–40,000, and for the responsible person within a legal entity from €100–1,000 to €400–4,000. For entrepreneurs and individuals, fines rose from €500–6,000 to €1,000–12,000, and from €100–1,000 to €200–4,000 for lesser violations.
The calculation of default interest on unpaid or overpaid tax also changes. Instead of the previous flat rate of 0.03% per day, the new rate consists of a base default-interest rate (the European Central Bank's main refinancing rate in effect on the first day of the half-year) plus three percentage points. The Tax Administration sets and publishes the rate every six months on its website and in the Official Gazette.
A significant part of the amendments builds new infrastructure for automatic tax-information exchange with EU member states — registration and reporting duties for crypto-asset service providers, digital platform operators (e.g. for property rentals), intermediaries in cross-border tax arrangements, and financial institutions. These rules follow EU directives (2023/2226, 2021/514) and are part of preparing the tax system for EU membership; the domestic registration and reporting duties already apply now, while full automatic exchange with EU tax authorities depends on future accession.
Practical takeaway: if a tax filing or payment is late, calculate interest using the new formula (ECB rate + 3 p.p.), not the old flat 0.03% daily rate. For companies, entrepreneurs and accountants, the key point is that misdemeanor fines for late or missing filings are now 3–4 times higher than before — it is worth double-checking internal deadlines for returns and reports.