Penále a úrok z prodlení

Under Czech law

Both instruments live in the Tax Procedure Code (Act No. 280/2009 Sb.). Penále (§ 251) attaches to additional assessments made by the tax office: 20 % of the tax increased or of a wrongly claimed deduction reduction (1 % where a reported tax loss is cut). It does not apply when the taxpayer files a corrective (dodatečné) return voluntarily before the office acts — the single strongest reason to self-correct early. Úrok z prodlení (§ 252) is late-payment interest on any tax unpaid when due, currently constructed from the CNB repo rate plus a statutory margin, running per day.

Both can be moderated: individual promíjení (waiver) under § 259 and the related guidance allows remission of penalties and interest in defined hardship and cooperation scenarios — partial as a rule, full only exceptionally.

A practical example

An e-shop discovers it misapplied VAT rates for a year, underpaying about 300 000 Kč. Filing corrective returns before any audit notice means paying the tax and interest but no 20 % penále — roughly a 60 000 Kč difference for moving first. Waiting for the audit would have cost the penalty and weakened any waiver application.

When you need a lawyer

Deciding between voluntary correction and defence, drafting waiver applications that meet the guidance''s criteria, and challenging interest calculations after long proceedings — where the office''s own delays inflated the bill.