A construction dispute in Silesia stalls for eight months. The reason: the court-appointed expert submitted a report that neither party had anticipated, and neither knew how to challenge it effectively. This scenario repeats itself across Polish civil, commercial, and administrative proceedings every year. Understanding how the expert witness system works – and where it can be turned to your advantage – is not optional for any party serious about litigation in Poland.
Polish court proceedings rely on court-appointed experts (biegli sądowi) to resolve technical, financial, and scientific questions that fall outside a judge's ordinary knowledge. These experts are drawn from official lists maintained by the presidents of regional courts (sądy okręgowe), and their opinions carry substantial evidentiary weight. A party that fails to challenge a flawed expert opinion within the prescribed procedural window – typically 14 days from service of the opinion – risks having that opinion treated as conclusive by the court.
This alert covers three areas: how experts are appointed and what rules govern them, what recent procedural developments mean for parties in active litigation, and what immediate steps you should take if an expert opinion has already been filed in your case. Each section includes a concrete action item with a deadline.
How are expert witnesses appointed in Polish proceedings?
The appointment mechanism is straightforward on paper. In practice, it generates significant tactical risk. Under the Kodeks postępowania cywilnego (Code of Civil Procedure, KPC), a court appoints an expert when a case requires specialist knowledge. The expert is selected from the list maintained by the president of the competent regional court, or – in exceptional cases – from outside that list. The court defines the scope of the expert's mandate in the appointment order, and that scope cannot be exceeded without a formal extension.
Three Polish institutions are central to this process. The regional court (sąd okręgowy) maintains the official expert register. The National Court Register (KRS) is sometimes consulted to verify corporate facts that experts rely upon. The Polish Financial Supervision Authority (KNF) is relevant when experts are appointed in financial market disputes. Knowing which body governs your expert's credentials matters when you need to challenge their qualifications.
The expert's opinion must be delivered within the deadline set by the court – often 30 to 90 days from appointment. Delays are common and can extend proceedings by months. A party may request that the court set a firm deadline and impose financial penalties on an expert who misses it. This tool is underused. Parties who monitor the expert's progress and apply procedural pressure consistently achieve faster outcomes.
- Verify that the appointed expert appears on the official regional court list
- Review the court's appointment order to confirm the scope of the mandate
- Note the expert's stated deadline and diarise a follow-up at the halfway point
What changed – and who is affected?
Polish civil procedure has undergone two significant shifts affecting expert evidence. First, amendments to the KPC introduced stricter rules on party-commissioned opinions (opinie prywatne). A private opinion submitted by a party is now treated as a factual assertion, not expert evidence. It does not carry the same weight as a court-appointed opinion. However, a well-constructed private opinion can compel the court to appoint a second court expert – which is often the real strategic goal. The threshold for triggering a second appointment is demonstrating a material deficiency or internal contradiction in the first opinion.
Second, the commercial courts (sądy gospodarcze) have adopted a more active case management approach. Judges now routinely set hard deadlines for parties to submit written questions to the expert before the opinion is drafted. Missing that window – which can be as short as 7 days from the court's order – forfeits your ability to shape the expert's mandate. That forfeiture is effectively irreversible within the same instance. We secured a successful challenge to an expert's financial methodology for a technology client in Mazowieckie (autumn 2025), but only because written objections were filed within the 7-day window. One day later would have closed that route entirely.
Parties involved in arbitration in Poland should note that institutional rules – including those of the Court of Arbitration at the Polish Chamber of Commerce – give tribunals broad discretion over expert appointments. The procedural protections available in state court proceedings do not automatically apply. A dispute lawyer advising on arbitration Poland matters must tailor the expert challenge strategy to the applicable rules.
What should you do immediately?
If an expert opinion has already been filed in your case, the 14-day response window under the KPC is the critical deadline. Within that period, you may submit written objections, request supplementation, or demand that the expert appear for oral examination. Failing to act within 14 days does not technically bar all future challenges – but it significantly weakens your position. Courts treat silence as partial acceptance. Personal liability for a poor litigation outcome rests with the party and its counsel, not the court.
For parties anticipating expert appointment – in construction disputes, IP valuation cases, KIO appeal proceedings, or sanctions compliance matters – the time to act is before the expert is appointed. Submit a written request specifying the questions you want the expert to address. If the opposing party has already proposed an expert, file an objection within the time allowed by the court's procedural order. Our team obtained a revised expert mandate for a German investor's subsidiary in Lower Silesia (spring 2026) by filing a targeted scope objection before the expert had begun work. The revised mandate excluded three questions that would have produced an unfavourable framing.
For cross-border matters – whether you are enforcing a foreign judgment or defending against one – expert evidence on Polish law or local market conditions can be decisive. The procedures for enforcing a United States judgment in Poland and for enforcing a UAE judgment in Poland both involve evidentiary hearings where expert opinions on Polish procedural conditions are regularly submitted. Knowing how to challenge or support those opinions is part of effective cross-border litigation strategy. Employment-related disputes – including those covered under workplace harassment employer duties under Polish law – also increasingly rely on psychological or HR expert opinions, where the same 14-day challenge window applies.
- Identify the date the expert opinion was served – the 14-day clock starts that day
- Prepare written objections addressing specific methodological or factual errors
- Request oral examination of the expert if written objections are insufficient
- In arbitration proceedings, check the applicable institutional rules before assuming KPC deadlines apply
- For cross-border disputes, assess whether a private opinion from a foreign expert can support a challenge
Specific situations require tailored responses. A party in a commercial dispute with a contested expert opinion has different options than a party in administrative proceedings before the National Appeals Chamber (KIO). The litigation Warsaw context – including the commercial court's active case management style – means that procedural inaction carries a higher cost here than in smaller regional courts.
To receive an expert assessment of your position on an expert witness challenge or appointment, contact info@kordeckipartners.com.
Frequently asked questions
Q: Can a party propose its own candidate for court-appointed expert?
A: Yes. Under the Code of Civil Procedure, a party may submit a written request naming a proposed expert, provided that person appears on the relevant regional court list. The court is not bound by this request, but judges in commercial proceedings often take it into account when both parties agree on a candidate. Submitting a joint proposal can reduce appointment delays by several weeks.
Q: What does a private expert opinion cost, and does it replace the court-appointed opinion?
A: A private opinion does not replace a court-appointed opinion. It is treated as a factual submission by the party. Costs vary widely – from PLN 5,000 for a straightforward accounting review to PLN 80,000 or more for complex technical or financial analyses. The strategic value lies not in replacing the court opinion but in demonstrating its deficiencies clearly enough to compel the court to appoint a second expert.
Q: Is it a common misconception that expert opinions are binding on the court?
A: It is. A court-appointed expert opinion is evidence, not a verdict. The court evaluates it alongside all other evidence and may depart from it if the opinion is internally inconsistent, based on incorrect assumptions, or contradicted by other reliable evidence. Parties who treat an unfavourable expert opinion as the end of the case often forfeit arguments they could have pursued through a well-timed challenge or a request for a supplementary opinion.
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 disputes. We work with Polish entrepreneurs, foreign investors, and in-house legal teams. 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.