A subtle start, serious consequences

A tax case doesn’t only begin with filing a tax return or receiving notice of an audit. According to Czech tax law, proceedings can be initiated ex officio—meaning the tax authority can start them based on internal checks, suspicion, or automated systems. This can happen when:

• a discrepancy is found between your tax return and third-party data,

• the office receives a report from another authority (such as social security or the police),

• unusual movements are detected in your business or personal accounts,

• there’s an automatic alert from the VAT or rental income system.

In these cases, the proceedings are launched without your request, and often without you realizing it. But that doesn’t mean they don’t affect you. Quite the opposite. Once the tax authority takes its first step, deadlines start ticking—and your silence may be interpreted as agreement or admission.

How do you know proceedings have actually started?

The initiation of proceedings can happen in different ways. Sometimes, you receive a formal letter. Other times, it’s just an email or even a phone call. What matters is that the tax authority makes what’s called an official act directed at the taxpayer—such as a request to provide information or submit documents. According to Czech case law:

“Tax proceedings are considered to have started the moment the tax authority takes its first action toward the taxpayer.”

That means a simple email or phone call may start the entire legal process, even if it doesn’t look official. If you ignore it, thinking it’s informal, you could lose valuable time—or your chance to respond.

What is ex officio initiation?

The tax office has the right to launch proceedings on its own—typically to reassess taxes, collect unpaid amounts, or review the accuracy of your return. This is called ex officio proceedings, and here’s what you need to know:

• You won’t necessarily receive a formal “notice” at the start.

• Just one official step from the authority is enough to trigger the case.

• All relevant deadlines start from that point.

Lawyer’s note: I often see people waiting weeks to respond, assuming the first contact “doesn’t count yet.” But this is exactly the danger. If you’re unsure whether the communication means formal proceedings have started, it’s better to ask a lawyer right away. If you wait too long, it may be too late to defend yourself—even if you were right all along.

Real-life example

A self-employed client received an email from the tax office suggesting he “may want to clarify payments received during a specific period.” Thinking it was informal, he waited three weeks before responding. By then, the office had already issued a reassessment. Even though he had valid documents, the court later rejected his defense—because he had a chance to respond earlier and didn’t.

Key takeaway

The start of proceedings is a critical moment—and you might not even realize it’s happening. Be alert from the very first contact with the tax office. Even a simple request might mean the clock is already ticking. If anything feels off, or if you’re unsure what a notice means, ask. Waiting too long can cost you.