A German investor's Warsaw subsidiary is locked in a construction dispute worth EUR 8m. The opposing party has filed a court-appointed expert opinion that, on closer reading, rests on contested methodology and ignores half the contractual documentation. The investor's counsel must now decide: challenge the opinion, request a supplementary hearing, or commission a competing private opinion. Each path carries a different cost, a different timeline, and a different risk of foreclosing future procedural options.
Expert witnesses play a decisive role in Polish civil and commercial court proceedings. Polish procedural law empowers courts to appoint registered experts from official lists maintained by district courts, and parties may also submit private opinions – though the two carry different evidentiary weight. Failure to challenge a flawed court-appointed opinion within the permitted procedural window can permanently foreclose the right to contest its conclusions, exposing the losing party to an adverse judgment it could have avoided.
This page explains how expert evidence works in Polish litigation, when and how to challenge it, what pitfalls foreign parties typically encounter, and how to protect your procedural position from the outset. The sections below move from the framework and appointment process through challenge mechanisms, cross-border considerations, and a practical readiness checklist.
How does the Polish court-appointed expert system work?
Polish civil procedure grants the court – not the parties – the primary power to appoint an expert witness. The court selects from lists of registered experts (biegli sądowi) maintained by each district court (sąd okręgowy). Registration requires a formal application, proof of qualifications, and a sworn oath. The National Court Register (KRS) does not maintain these lists; each district court manages its own, which means the quality and depth of expertise varies significantly by region.
The court defines the expert's mandate in a formal order. That order sets out the specific questions the expert must answer, the documents available for review, and the deadline for submission – typically 60 to 120 days from appointment, though delays of six months or more are common in complex construction, IT, or valuation cases. The expert submits a written opinion, which is served on both parties.
Once the opinion is served, parties have a right to comment in writing and to request that the expert appear at a hearing for oral examination. This is a critical procedural moment. A party that fails to raise specific objections promptly risks having the court treat silence as acceptance. In practice, many foreign parties miss this window simply because their counsel does not flag the deadline clearly enough.
The Polish Financial Supervision Authority (KNF) and other regulatory bodies maintain their own specialist panels, but these are separate from the court-expert system and rarely intersect in commercial litigation.
What procedural rights do parties hold over expert evidence?
Parties are not passive recipients of expert opinions. Polish procedural law provides at least four distinct levers. First, a party may file written objections to the opinion and request supplementary questions. Second, a party may request oral examination of the expert at a hearing. Third, where the court-appointed opinion is seriously flawed, a party may request appointment of a different expert or a panel of experts. Fourth, a party may submit a private opinion – though this is treated as a document, not expert evidence, unless the court decides to give it equivalent weight.
The distinction between a court-appointed opinion and a private opinion matters enormously in practice. We secured a reversal of an adverse interlocutory ruling for a manufacturing client in the Mazowieckie region (autumn 2025) precisely by demonstrating that the court-appointed expert had applied an outdated technical standard. The key was submitting a well-structured private opinion alongside a targeted written objection – filed within 14 days of service of the court opinion.
Consider the decision matrix:
- Opinion has methodological errors → file written objection + private opinion within 14 days
- Expert applied wrong legal standard → request oral hearing + supplementary questions
- Opinion is internally contradictory → motion for replacement expert or expert panel
- Expert exceeded mandate → formal objection on procedural grounds
- Opinion is largely sound but one figure is contested → targeted supplementary question
Missing the 14-day window does not automatically forfeit all rights, but it substantially weakens the party's position. Courts treat late objections with visible scepticism. The irreversible consequence is that a flawed opinion, left unchallenged, becomes the evidentiary foundation for the judgment.
For parties involved in procurement disputes, a parallel mechanism exists before the National Appeals Chamber (Krajowa Izba Odwoławcza, KIO). A KIO appeal has a strict 10-day filing deadline and its own rules on expert evidence, which differ from general civil procedure. Missing that window forecloses the procurement challenge entirely.
What are the most common pitfalls for foreign parties?
Foreign investors and their counsel frequently underestimate the procedural formalism of Polish courts. Three patterns recur. First, parties treat the expert opinion as a fait accompli rather than a contestable document. Second, parties commission a private opinion without simultaneously filing procedural objections, so the private opinion sits in the file without being linked to a concrete challenge. Third, parties fail to verify whether the court-appointed expert is actually registered for the relevant discipline – an expert appointed outside their registered specialty can be disqualified, but only if the objection is raised before the expert submits the opinion.
Language is a separate source of risk. Expert opinions in Polish courts are prepared in Polish. A foreign party that relies on an internal translation without qualified legal review may miss technical nuances that are decisive for the challenge strategy. Under Polish civil procedure, foreign-language documents must be accompanied by a certified translation; the same applies to private opinions submitted by foreign-party experts.
There is also a cost dimension. Court-appointed experts are remunerated from an advance deposited by the requesting party – typically PLN 3,000 to PLN 15,000 for standard commercial cases, though complex construction or IP valuations can exceed PLN 50,000. If the advance is insufficient, the expert may suspend work, causing delays that cascade through the trial schedule. Parties should budget realistically and challenge the advance estimate early if it appears low.
We obtained interim measures protecting assets worth over EUR 3m for a Silesian manufacturing group (spring 2026) by pairing an expert challenge with a precautionary attachment motion – a combination that the opposing party had not anticipated and could not counter within the procedural timeframe.
How do cross-border and arbitration considerations affect expert evidence in Poland?
Poland-seated arbitration proceedings – whether under the rules of the Court of Arbitration at the Polish Chamber of Commerce or an ICC tribunal seated in Warsaw – follow different rules on expert evidence. Arbitral tribunals have wider discretion: they may appoint experts, allow party-appointed experts to testify concurrently ("hot-tubbing"), and apply IBA Rules on the Taking of Evidence. None of these mechanisms exist in Polish state-court proceedings.
For cross-border disputes involving enforcement of foreign judgments in Poland, expert evidence may re-emerge at the enforcement stage. If a Ukrainian or German court judgment is being enforced in Poland, the Polish court may require expert evidence on the content of foreign law or the equivalence of procedural standards. Our team advises on enforcing a Ukraine judgment in Poland step by step, including how to prepare expert evidence on Ukrainian procedural law for Polish court review.
Sanctions compliance has introduced a new layer of complexity. Where a dispute involves a party subject to EU or US sanctions, expert evidence on the legality of underlying contracts or asset valuations may be required. Courts have begun appointing experts in international trade law and sanctions compliance – a specialist category that barely existed in Polish court lists five years ago. Parties should verify whether a suitable registered expert exists before the court appoints a generalist.
For foreign investors structuring their Polish presence, the choice of dispute resolution mechanism at the contract stage determines the expert-evidence rules that will apply later. A well-drafted arbitration clause can preserve access to party-appointed experts and avoid the delays inherent in the state-court appointment system. Our corporate and M&A team addresses these structural choices as part of corporate and M&A advisory in Poland.
Cyprus-based holding structures present a recurring pattern. A Cyprus holding company with a Polish operating subsidiary that enters Polish litigation faces questions about which expert evidence rules apply to intra-group transactions. We address the full procedural picture for such structures in our guide on dispute resolution for Cyprus companies doing business in Poland.
What is the self-assessment checklist before engaging an expert witness strategy?
Before committing to a specific expert evidence strategy, a party should work through five questions. Is the court-appointed expert registered for the relevant discipline? Has the expert's mandate been defined narrowly enough to prevent overreach? Has the advance deposit been set at a realistic level? Is there a qualified Polish-language expert available to prepare a competing private opinion within the objection window? And has the party's counsel identified the precise procedural moment at which silence will be treated as acceptance?
The practical checklist:
- Verify the expert's registration category against the district court list before appointment is finalised
- Review the court's mandate order on receipt – challenge scope errors within 7 days
- Set a calendar alert for the 14-day written objection window from service of the opinion
- Commission a private opinion from a qualified specialist immediately upon receiving the court opinion
- Budget PLN 5,000 to PLN 50,000 for expert costs depending on case complexity
Three business scenarios illustrate the stakes. A Warsaw IT company disputing a software development contract needs a court-appointed expert in software engineering – a category where the district court lists are thin and delays of nine months are common; early identification of a suitable expert and a motion to name a specific candidate can halve the wait. A Małopolska manufacturing firm facing a product liability claim needs an expert in industrial safety standards – where private opinions from accredited testing institutes carry significant persuasive weight if properly introduced. A foreign investor challenging a real estate valuation needs an expert in property appraisal methodology – where the gap between court-list experts and market-practice valuers can be significant, and a well-prepared challenge can shift the valuation by 20 to 30 percent.
Dispute lawyers working on these matters must also coordinate with the client's internal technical teams. The expert's questions are legal in form but technical in substance. A litigation lawyer who does not understand the technical domain will miss the methodological errors that make a challenge viable.
Specific situation calls for specific action. If your company is facing a court-appointed expert opinion that appears flawed – or if you are entering litigation where expert evidence will be central – the procedural window to act is shorter than most parties assume. Delay forfeits options that cannot be recovered later.
To receive an expert assessment of your expert-evidence strategy in Polish proceedings, contact info@kordeckipartners.com.
Frequently asked questions
Q: Can a party in Polish litigation nominate its own preferred expert for court appointment?
A: A party may submit a motion requesting that the court appoint a specific person from the district court's registered list. The court is not bound by this request but will typically consider it, particularly if the party demonstrates the nominee's specialist qualifications. The motion should be filed early – ideally at the case-management stage – before the court makes its own selection. Waiting until after appointment is ordered rarely succeeds.
Q: How long does the expert-opinion process typically add to Polish commercial litigation?
A: In straightforward commercial disputes, a court-appointed opinion typically adds four to six months to the proceedings. In construction, IT, or complex valuation cases, the delay is commonly nine to eighteen months, particularly where supplementary opinions or expert hearings are required. Parties should factor this into settlement timing and any parallel enforcement strategy. Requesting a specific expert known for timely delivery can reduce delays by two to three months.
Q: Is a private opinion submitted by the party treated as expert evidence by a Polish court?
A: Under Polish civil procedure, a private opinion is formally classified as a document – not as expert evidence. It does not carry the same evidentiary weight as a court-appointed opinion. However, a well-prepared private opinion can persuade the court to appoint a new expert, to ask supplementary questions, or to discount the court-appointed opinion's conclusions. Its practical value depends heavily on how it is introduced and linked to specific procedural objections. Submitting a private opinion without accompanying procedural motions significantly reduces its impact.
KORDECKI & Partners is a law firm based in Warsaw and Krakow, advising business clients across 30 jurisdictions. Our team combines expertise in Polish and international law with a practical approach to commercial litigation, arbitration, and expert-evidence strategy. We work with Polish entrepreneurs, foreign investors, and in-house legal teams facing disputes in Polish state courts and arbitral tribunals. To discuss your situation, contact info@kordeckipartners.com.
Disclaimer: This publication is provided for informational purposes only and does not constitute legal advice. The information herein should not be relied upon as a substitute for professional legal counsel tailored to your specific circumstances. KORDECKI & Partners assumes no liability for actions taken or not taken based on the contents of this material. For advice regarding your particular situation, please contact info@kordeckipartners.com.