Challenge to an arbitrator in the Czech Republic: step by step

A CFO overseeing a Prague-seated arbitration receives a co-arbitrator's disclosure that raises doubt about independence, days before a decisive hearing. The clock for a challenge to an arbitrator starts running from the day the ground becomes known, not from the day the tribunal was constituted, and it does not pause for internal sign-off.

A challenge to an arbitrator in Czech-seated arbitration follows Czech arbitration legislation, or the institution's rules where one applies; the ground must be raised without delay after it becomes known, and the ruling body – tribunal, institution, or, on refusal, a Czech court – depends on the seat and the rules the parties chose.

What follows sets out, step by step, who may file, the deadline that runs from actual knowledge, the document set a Czech court or institution expects, and the point at which the matter is either resolved internally or moves to litigation.

When does a challenge to an arbitrator arise in Czech-seated arbitration?

A challenge becomes possible the moment a party learns of a fact that puts the arbitrator's independence, impartiality, or agreed qualification in doubt. The ground, not the appointment date, starts the clock.

Doubt typically surfaces through a late disclosure, a prior professional relationship the arbitrator did not flag, or a qualification the jurisdiction clause required but the appointee does not hold. Under Czech arbitration legislation, a party that already knew the ground when it agreed to the appointment cannot revive it later as a challenge. Waiting to see how the tribunal rules before raising a known doubt closes that route once the deadline runs out; the ground cannot be raised again on appeal in the same form.

The disclosure duty runs on the arbitrator, not on the party researching the arbitrator's history.

Who can file, and what makes a challenge admissible?

Either party to the Czech-seated arbitration may file, including the party that nominated the arbitrator being challenged, provided the ground arose or became known after the nomination. Admissibility turns on form, timing, and the specificity of the stated ground.

The challenge is filed in writing with the tribunal or, where the parties adopted institutional rules, with the body administering the case; the correct addressee follows the arbitration seated in Prague under the rules the parties chose, a distinction our note on arbitration seated in Prague sets out for foreign counsel unfamiliar with the split between the statute and the institutional rule. A vague reference to concerns about neutrality, without a stated fact, is routinely treated as inadmissible. A German manufacturer's challenge to a co-arbitrator advanced within weeks after the disclosure gap, rather than the earlier advice itself, was named as the ground (autumn 2025).

A challenge filed without the disclosure timeline documented rarely survives scrutiny, and a missed admissibility point cannot be refiled once the tribunal or institution has ruled. LISTINA prepares a factual disclosure and timeline report – the record of what was known, and when – within five to eight working days; write to info@listinafirm.com. Representation before the tribunal or a Czech court, if it becomes necessary, is provided by a collaborating advocate.

What is the route, step by step, and what is the binding deadline?

The route runs from the written challenge, through the tribunal's or institution's decision, to a Czech court only if that decision is unfavourable and the seat is in the Czech Republic. Each stage carries its own short deadline, counted from actual knowledge or from receipt of the decision, depending on which rule applies.

• Ground becomes known – the party notes the date and the source of knowledge.
• Written challenge filed with the tribunal or the administering institution.
• Challenged arbitrator may withdraw voluntarily, closing the matter without a ruling.
• Tribunal or institution decides; on refusal, the challenging party may apply to a Czech court.
• Court reviews the refusal; its decision on the challenge is not subject to further ordinary appeal.

• Ground known, arbitrator still active – file the written challenge without delay; the challenging party acts.
• Institution's own deadline applies – the administering body decides within the period its rules set.
• Tribunal or institution refuses – the challenging party may apply to the competent Czech court, again within a short period.
• An interim measure is needed while the challenge is pending – a separate application, not the challenge itself, preserves the position.

The deadline for raising a known ground runs in days, not months, and it is not suspended by settlement talks or by an interim measure filed in parallel. A party that lets the period lapse loses the ground even where the doubt about the arbitrator later proves justified.

A refusal by the institution is not the same event as a refusal by the court, and each has its own clock.

What must the file contain?

A challenge stands or falls on the paper trail: the date the ground became known, the source of that knowledge, and the specific fact relied on, distinct from any general disagreement with how the arbitrator has conducted the case.

• The arbitration agreement or jurisdiction clause naming the seat and the applicable rules.
• The arbitrator's disclosure statement, if one was made, and the date it was received.
• Correspondence or public record showing when the ground became known to the challenging party.
• The written challenge itself, dated and addressed to the correct body.
• Any prior submissions referencing the same arbitrator, to rule out an earlier waiver.
• Powers of attorney, where the party acts through counsel or a foreign representative.

Where the party or a witness is outside the Czech Republic, taking evidence abroad and the power-of-attorney form follow rules our note on evidence before a Czech court and power-of-attorney requirements sets out; a foreign-executed power of attorney that lacks the required form is a common reason a challenge stalls on admissibility rather than on its merits. An Austrian holding company's file was reconstructed to show the disclosure gap predated the hearing by eleven months, moving the challenge from the tribunal to the reviewing Czech court within a single quarter (winter 2025).

A file assembled after the deadline has run cannot be repaired by better argument. LISTINA reconstructs the disclosure timeline and assembles the document set from what the register, the correspondence, and the arbitration file actually show, delivered within five to eight working days; write to info@listinafirm.com. Representation before the tribunal or a Czech court, where required, is provided by a collaborating advocate.

Act, wait, or stop: the decision point

Once the ground and its date of knowledge are documented, the choice is narrow: file within the short deadline, wait only if the ground is not yet fully known, or stop if the party already accepted the arbitrator with knowledge of the fact now in question.

A documents-and-registers review can establish what was disclosed, when, and to whom, and whether a public record contradicts the arbitrator's statement. It cannot establish what a party subjectively knew before that date, and it cannot predict how a tribunal or a Czech court will weigh a borderline disclosure gap.

A party already exposed to a counterparty's insolvency faces a further complication: a challenge that succeeds too late to affect the award may still leave the underlying claim to be pursued through the insolvency estate, where our note on registering a claim in insolvency sets out the parallel deadline that keeps running regardless of the arbitration's outcome. Missing both clocks at once is the failure this page is written to prevent.

Frequently asked questions

What does challenge to an arbitrator cost in time?

Time, not fee, is the constraint: the written challenge must be filed within days of the ground becoming known, and the tribunal or institution then decides within the period its own rules set, typically a matter of weeks. A court review, if it follows, runs on a further, separate clock.

Which form is used?

There is no single official form. The challenge is a written submission stating the ground, the date it became known, and the relief sought, filed with the tribunal or the institution administering the arbitration under the rules the parties chose.

Is a representative required?

A party may file the challenge itself. Where the matter proceeds to a Czech court, representation follows the ordinary rules for that court; LISTINA works with a collaborating advocate where representation becomes necessary and does not itself represent parties.

What if the party is abroad?

A foreign party files through the same route, with a power of attorney meeting Czech form requirements where counsel acts on its behalf, and with attention to how the deadline is counted where notice was received outside the Czech Republic.

LISTINA produces factual reports from documents and public registers. It does not provide legal advice and does not represent parties. Where a matter requires representation before a Czech court or authority, it is handled by a collaborating advocate.

Tereza Kolářová works on court practice, procedure and evidence. He writes on how a Czech case file is built and read.

A challenge to an arbitrator is a narrow, fast-moving procedure, and the record that supports it has to exist before the deadline, not after it. LISTINA delivers the factual timeline and document report within five to eight working days; write to info@listinafirm.com. Representation before the tribunal or a Czech court, if needed, is provided by a collaborating advocate.