Both Slovakia and the Czech Republic penalise late filing, late payment and under-declared tax, but the amounts and mechanics differ. Slovakia fines a late return between EUR 100 and EUR 30,000 and charges late-payment interest of at least 15% a year, while the Czech Republic sets the late-filing penalty at 0.05% of the tax per day (capped at CZK 300,000) and charges interest of the ČNB repo rate plus 8 points, 11.75% a year in the second half of 2026.
What penalties do the two tax codes impose?
In both countries the rules sit in a single procedural code: the Slovak Tax Code (Act No. 563/2009 Coll.) and the Czech Tax Code (Act No. 280/2009 Coll.). Each distinguishes a penalty for a paperwork breach, such as a missing or late return, from interest for paying tax late, and from an additional charge tied to tax assessed by the authority. Because they punish different failures, more than one can apply to the same case.
The practical takeaway is the same on both sides of the border: filing on time and paying on time removes almost all exposure. A business operating in both markets, as our Slovak tax advisory overview notes, needs two separate compliance calendars rather than one.
How much is the penalty for a late tax return?
In Slovakia the tax office imposes a discretionary fine of EUR 100 to EUR 30,000 for filing a return late or not at all, with the amount reflecting how serious and how long the delay was. In the Czech Republic the penalty is formula-based: 0.05% of the assessed tax for each day of delay, capped at 5% of the tax and at CZK 300,000, and it is only charged once the delay exceeds five working days.
Both systems offer a legitimate way to buy time. In Slovakia you can extend the deadline by simple notification, usually by three months; in the Czech Republic a return handled by a registered tax adviser under power of attorney is due six months after the year-end instead of three.
How is interest on late payment calculated?
Interest is where the two regimes look most alike in structure but differ in the number. Slovakia charges four times the ECB base rate, but never less than 15% a year, which is the rate that applies in practice today; it runs for each day of delay for up to four years. The Czech Republic charges the ČNB repo rate plus 8 percentage points, which is 11.75% a year for the second half of 2026, and it starts only from the fourth day of delay.
In both countries interest accrues daily, so a partial payment always reduces it. For EUR 1,000 of Slovak arrears over 90 days the interest is about EUR 37; for CZK 50,000 of Czech arrears over the same period it is about CZK 1,449.
What extra charge applies after a tax audit?
The biggest structural difference appears when the authority finds under-declared tax. In Slovakia the fine depends on who found the error: correcting it yourself before an audit costs one times the ECB rate a year (at least 3%), while an error found by the audit costs three times the rate (at least 10%) of the additional tax, and never more than that tax itself. In the Czech Republic a separate penalty of 20% of the additionally assessed tax applies, but only when the tax is assessed by the authority, typically after an audit.
The lesson is identical in both countries: a voluntary correction is far cheaper than waiting for the inspector. In the Czech case a voluntary supplementary return avoids the 20% penalty entirely, though not the interest.
Can penalties be reduced or waived?
Slovakia built leniency into the law itself: since 1 January 2024 a second chance means the first breach of certain obligations triggers a call to remedy rather than a fine. The Czech Republic relies instead on individual waiver: you can ask the tax authority to remit a penalty or interest, and it weighs the reasons and your cooperation. Neither route is a substitute for compliance, and neither removes interest automatically.
How can you avoid penalties in both countries?
The playbook is the same regardless of jurisdiction. Diarise every filing and payment date with a few days to spare, use the available deadline extension where you expect to be late, and correct any error voluntarily before the authority spots it. If arrears already exist, act at once, because interest runs every day and part-payment shrinks it. Sound bookkeeping is what makes all of this routine, which is where professional accounting for companies earns its keep.
Have you received a penalty notice from the tax authority in Slovakia or the Czech Republic and are unsure whether it is justified or how to respond? We will review your deadlines and filings, prepare a supplementary return or a waiver request and set up your calendar so penalties stop recurring.
FAQ
How much is the fine for a late tax return?
In Slovakia the tax office imposes a discretionary fine of EUR 100 to EUR 30,000. In the Czech Republic the penalty is 0.05% of the tax per day, capped at 5% and at CZK 300,000, and it is only charged once the delay exceeds five working days. Both countries let you extend the deadline in advance.
What is the late-payment interest rate in 2026?
Slovakia charges four times the ECB base rate, but at least 15% a year, which is the rate in force today. The Czech Republic charges the ČNB repo rate plus 8 percentage points, which is 11.75% a year in the second half of 2026 and starts from the fourth day of delay. In both cases interest accrues daily.
What happens if an audit finds under-declared tax?
In Slovakia the fine is three times the ECB rate a year, at least 10% of the additional tax, when the audit finds the error, but only 3% if you correct it voluntarily first. In the Czech Republic a 20% penalty applies, but only on tax assessed by the authority, so a voluntary supplementary return avoids it.