A Warsaw-based IT company is midway through a construction dispute when the opposing party challenges the technical findings the case hinges on. The court appoints an expert. Months pass. The expert's opinion arrives late, contains assumptions your counsel disputes, and the court treats it as near-conclusive. At that point, the window to challenge the methodology has effectively closed.
Expert witnesses in Polish court proceedings are appointed by the court from an official register maintained by the sąd okręgowy (regional court) or, in commercial arbitration, by the parties themselves. The expert's written opinion carries significant evidential weight – courts rarely depart from it without a compelling counter-opinion. Parties may challenge an expert's qualifications or methodology, but procedural deadlines for doing so are strict and missing them forfeits the right entirely.
This guide walks through the appointment procedure, the timeline and costs involved, the most effective challenge strategies, and the specific risks that arise in cross-border disputes. Three business scenarios illustrate how the rules apply in practice – for a manufacturing company, a foreign investor, and a technology firm with IP at stake.
How does the expert witness appointment process work in Poland?
Polish civil procedure assigns the court full control over expert appointments. A party cannot unilaterally introduce a binding expert opinion. The court decides whether expert evidence is necessary, selects the expert, and frames the questions put to them. This differs sharply from adversarial systems where each side retains its own expert.
The National Court Register (KRS) does not maintain the expert list – that function sits with each regional court. Every sąd okręgowy keeps a register of court-certified experts (biegły sądowy) organised by discipline: construction, accounting, IT, valuation, medicine, and dozens of others. Experts on this list have passed a vetting process and taken an oath. Courts strongly prefer list-registered experts, though they may appoint an unregistered specialist when the required discipline is absent from the register.
A party seeking expert evidence must file a formal motion specifying the subject matter, the questions proposed, and the relevance of the evidence to disputed facts. The court may accept, modify, or reject those questions. Once appointed, the expert has a deadline – typically 30 to 90 days – set by the court in the appointment order. Extensions are common but require court approval.
- File the motion with proposed expert questions and a deposit advance
- Court issues an appointment order identifying the expert and deadline
- Expert reviews case files and, where relevant, conducts a site visit
- Written opinion submitted to the court and served on all parties
- Parties submit written observations within a court-set period (usually 14 days)
The deposit advance for expert costs is paid by the requesting party upfront – typically between PLN 2,000 and PLN 15,000 for standard commercial matters, though complex valuations or forensic accounting opinions can exceed PLN 50,000. Final costs are allocated in the judgment.
What are the timelines and costs parties should plan for?
Expert proceedings extend litigation materially. In commercial disputes before the district courts in Warsaw, the period from appointment motion to delivery of the written opinion averages four to eight months. Complex matters – multi-site construction defect claims, IP valuation, or forensic accounting – can run twelve months or longer. Planning a dispute strategy without accounting for this timeline is one of the most common and costly mistakes foreign parties make.
The Polish Financial Supervision Authority (KNF) and other regulatory bodies maintain their own expert pools for administrative proceedings, but in civil litigation the regional court list governs. Parties in Warsaw proceedings have noted that the most sought-after accounting and valuation experts carry backlogs exceeding six months before they can begin substantive work. This is not an administrative delay – it is a capacity constraint built into the system.
Cost structures vary by discipline and case complexity. A standard accounting opinion in a commercial dispute costs between PLN 5,000 and PLN 20,000. A real-estate valuation runs PLN 3,000 to PLN 12,000. IT forensics or software valuation opinions regularly exceed PLN 30,000 and can reach PLN 100,000 in major technology disputes. These figures are estimates; courts set actual remuneration under a regulatory tariff.
We secured a favourable outcome in a forensic accounting dispute for a manufacturing client in the Mazowieckie region (autumn 2025) by filing a detailed challenge to the expert's methodology within the 14-day observation window – a step the opposing party missed entirely, forfeiting its right to contest the core findings.
For cross-border matters, parties enforcing foreign judgments in Poland should note that expert evidence gathered abroad does not automatically carry equivalent weight. The procedure for enforcing a Luxembourg judgment in Poland illustrates how foreign evidentiary standards interact with Polish procedural requirements.
How can parties challenge an expert opinion effectively?
Challenging an expert opinion is procedurally possible but strategically demanding. The court is not required to accept a party's objections. However, a well-structured challenge – grounded in methodological error, factual omission, or conflict of interest – can compel the court to order a supplementary opinion or appoint a second expert. Missing the observation deadline precludes all of these options and forfeits the argument permanently.
Three grounds commonly succeed in practice. First, methodological error: the expert applied an incorrect valuation standard or relied on assumptions not supported by the evidence in the file. Second, factual incompleteness: the expert failed to inspect a key asset, review a relevant contract, or address a question framed in the appointment order. Third, conflict of interest: the expert has a prior relationship with one of the parties or their counsel.
A party wishing to challenge must file written observations within the period set by the court – typically 14 days from service of the opinion. Those observations should be precise. Vague objections ("the opinion is incorrect") carry no procedural weight. The observations must identify the specific passage disputed, the correct methodology or fact, and the source supporting the alternative position.
If the court finds the challenge substantiated, it may order the same expert to prepare a supplementary opinion addressing the objections, or appoint an entirely new expert. The second path is more disruptive to the opposing party but adds three to six months to proceedings. In high-value disputes, that delay can itself be a negotiating lever.
Our team obtained interim measures protecting assets worth over EUR 3m for a German investor's subsidiary in Lower Silesia (spring 2026) in part because we filed a pre-emptive challenge to the opposing party's proposed expert questions, narrowing the scope of the opinion before it was written.
What specific risks arise in cross-border and arbitration proceedings?
Foreign parties in Polish litigation face a structural disadvantage: they are unfamiliar with which experts on the regional court register carry genuine authority in their discipline, and which are routinely challenged for superficial work. That information gap is not visible in the register itself. A dispute lawyer with local market knowledge closes that gap before the appointment order is issued.
In arbitration Poland proceedings – whether before the Court of Arbitration at the Polish Chamber of Commerce or an international tribunal seated in Warsaw – the rules differ. Parties may jointly appoint an expert or each present their own expert opinion. The tribunal is not bound by the court register. This flexibility is significant: parties can retain internationally recognised specialists whose methodologies align with the governing law of the contract.
Sanctions compliance adds a further layer in cross-border disputes. Where the opposing party or the subject matter of the dispute involves sanctioned entities or assets, the expert's access to information may be restricted. Counsel must advise the court of these constraints at the outset; failure to do so can result in an opinion based on incomplete data that nonetheless binds the proceedings.
KIO appeal proceedings – challenges before the National Appeals Chamber (Krajowa Izba Odwoławcza) in public procurement disputes – follow a compressed timeline. Expert opinions in KIO matters must be delivered within days, not months. The standard civil procedure timeline is irrelevant here; parties must prepare expert evidence in advance of filing the appeal.
For parties whose disputes involve data protection or digital evidence, the intersection of expert evidence with regulatory findings is increasingly relevant. The approach taken by the Personal Data Protection Office (UODO) in enforcement proceedings, discussed in our analysis of GDPR fines in Poland and UODO enforcement trends, affects how digital forensic experts frame their opinions in related civil litigation.
Three business scenarios: manufacturing, IT, and foreign investor
Understanding the rules in the abstract is useful. Seeing how they apply to concrete business situations is more so. The three scenarios below cover the most common configurations our clients encounter.
Manufacturing company – construction defect dispute. A Silesia-based manufacturer claims the newly built production facility has structural defects causing operational losses. The court appoints a construction engineering expert. The key risk: the expert's site visit occurs eighteen months after the defects first appeared, and the manufacturer has since made partial repairs. Evidence of the original defect is incomplete. Counsel should document defects thoroughly before any repair work begins and preserve photographic, engineering, and contractor records. Filing those records with the court before the expert visit shapes the factual basis of the opinion.
IT company – software valuation dispute. A Warsaw-based software company is in a shareholder dispute where the core issue is the value of the company's proprietary platform. The court-appointed valuation expert has an accounting background but limited software industry experience. Counsel files observations challenging the expert's use of a cost-based rather than income-based methodology, citing the company's recurring revenue model. The court orders a supplementary opinion addressing the income approach. The revised valuation is materially higher, directly affecting the settlement range.
Foreign investor – cross-border enforcement. A UAE-based investor seeks to enforce a foreign arbitral award in Poland against a Polish counterparty that disputes the factual findings underlying the award. The Polish enforcement court may admit expert evidence on the foreign law applied in the arbitration. Counsel must prepare a foreign law expert opinion in advance. The procedure for enforcing a UAE judgment in Poland provides the procedural framework within which that expert evidence operates.
Each scenario illustrates the same principle: the outcome of expert proceedings is shaped more by preparation before the appointment order than by arguments made after the opinion is delivered.
Specific situations in cross-border disputes require early assessment. A delayed challenge or a missed observation deadline forfeits rights that cannot be recovered at a later stage of proceedings.
To receive an expert assessment of your dispute strategy in Polish court or arbitration proceedings, contact info@kordeckipartners.com.
Frequently asked questions
Q: Can a party in Polish civil proceedings retain its own expert instead of relying on the court-appointed expert?
A: A party may commission a private expert opinion and submit it as a documentary exhibit. However, this private opinion does not carry the same procedural weight as the court-appointed expert's findings. The court is not required to treat the two opinions equally. A private opinion is most effective when used to frame the observations challenging the court expert's methodology, rather than as a standalone substitute for the court-appointed opinion. The cost of a private opinion is generally not recoverable in the judgment.
Q: How long does the entire expert evidence procedure typically take in a Warsaw commercial dispute?
A: From the filing of the appointment motion to the delivery of the written opinion, parties should plan for four to eight months in standard commercial matters. Complex forensic accounting or multi-site construction opinions routinely take twelve months or more. After delivery, the 14-day observation period adds further time, and if the court orders a supplementary opinion, add another three to six months. Parties who underestimate this timeline consistently find themselves in settlement negotiations from a weaker position than anticipated.
Q: Is it possible to challenge the expert's qualifications before the opinion is written?
A: Yes. Polish civil procedure allows a party to file a challenge to the expert's appointment on grounds of conflict of interest or lack of relevant qualifications. This challenge must be filed promptly – ideally within 14 days of receiving the appointment order. A common misconception is that qualifications can be challenged at any point during proceedings. In practice, courts treat late-stage qualification challenges as an attempt to delay proceedings and routinely dismiss them. Acting immediately upon receiving the appointment order is the only reliable window.
About KORDECKI & Partners
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 cross-border dispute resolution. We work with Polish entrepreneurs, foreign investors, and in-house legal teams navigating Polish court proceedings. 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.