A Warsaw-based technology company is locked in a contract dispute worth several million zlotys. The opposing party has filed a motion for a court-appointed expert. Your counsel has two weeks to respond, challenge the proposed expert's credentials, or submit your own questions. Miss that window, and the expert's terms of reference are set without your input – a position that is very difficult to reverse.

Polish court proceedings rely heavily on court-appointed expert witnesses (biegli sądowi) to resolve technical, financial, and specialist disputes. These experts are drawn from lists maintained by district courts across Poland, and their opinions carry significant evidentiary weight before the bench. A party that understands how to engage with this process – from appointment through to challenge – holds a material procedural advantage.

This guide walks through the appointment procedure step by step, explains how costs and timelines work in practice, and identifies the mistakes that most often damage a client's position. Three business scenarios illustrate how the process plays out for a domestic manufacturer, a Warsaw-based IT firm, and a foreign investor operating in Poland.

How are expert witnesses appointed in Polish civil proceedings?

The appointment mechanism is governed by the Kodeks postępowania cywilnego (Code of Civil Procedure, KPC). The court issues a formal appointment order, defines the scope of the expert's mandate, and sets a deadline for delivery of the written opinion – typically 30 to 90 days from appointment. The court may appoint an expert on its own motion or at a party's request.

Experts are selected from regional lists held by each Sąd Okręgowy (Regional Court). The National Court Register (KRS) does not maintain these lists, but the Ministry of Justice publishes a consolidated online directory. Parties may propose a specific expert by name. The court is not bound by that proposal, but it is rarely ignored when the candidate holds recognised specialist credentials.

The appointment order defines the questions the expert must answer. This is the most consequential document in the entire process. A narrowly drafted question produces a narrow answer. Parties have the right to submit proposed questions before the order is issued. Missing this step forfeits your ability to shape the evidentiary record.

  • File proposed expert questions in writing before the appointment hearing.
  • Check the regional court's expert list for candidates with the relevant specialisation.
  • Review any prior opinions filed by the proposed expert in published case law.
  • Confirm the expert is not conflicted – prior engagement by the opposing party is a ground for exclusion.
  • Request a copy of the appointment order immediately after it is issued.

The Polish Financial Supervision Authority (KNF) and sector regulators sometimes publish technical standards that an expert in financial or capital-market disputes must apply. Pointing the court to those standards in your proposed questions anchors the expert's analysis to a recognised benchmark.

What does the expert opinion procedure look like in practice?

Once appointed, the expert receives the case file and any physical materials the court directs to be submitted. The written opinion must address each question in the appointment order. Delivery deadlines range from 30 days for straightforward valuations to six months or more for complex construction or accounting matters. The court can extend the deadline, but delays are common – and costly.

We secured a favourable outcome in a construction defect dispute for a developer client in Małopolska (autumn 2025). The opposing party's expert had exceeded the scope of the appointment order by addressing questions not put to him. We filed a timely objection, and the court excluded those portions of the opinion. The remaining findings supported our client's position.

After the written opinion is filed, each party has the right to submit written questions (zarzuty do opinii). The court then decides whether to require the expert to respond in writing or to appear at a hearing for oral examination. Oral examination is the sharper tool: it allows counsel to probe the expert's methodology in real time. Parties who rely solely on written objections often leave critical assumptions uncontested.

One practical point that is frequently overlooked: the expert is entitled to remuneration from a deposit paid by the requesting party. The deposit is set by the court – commonly between PLN 2,000 and PLN 15,000 for standard disputes, and substantially higher for complex financial or engineering matters. Failure to pay the deposit within the court's deadline results in the expert not being appointed at all, stalling the proceedings.

When can a party challenge or replace an expert witness?

Polish procedural law provides two main routes for challenging an expert. First, a party may apply to exclude the expert on grounds of bias or conflict of interest – the same grounds that apply to judicial recusal. This application must be filed promptly, before the expert submits the opinion, or the right is lost. Personal liability does not arise here, but the procedural consequence is irreversible: a late challenge is dismissed without examination.

Second, a party may request a supplementary opinion (opinia uzupełniająca) or a second expert opinion (opinia innego biegłego). The court grants a second opinion only when the first is internally contradictory, incomplete, or based on factual errors. Disagreement with the expert's conclusions alone is not sufficient. This distinction matters enormously in practice – framing the request correctly is the difference between a new opinion and a rejection.

We obtained interim measures protecting a client's assets worth over EUR 3m for a German investor's subsidiary in Lower Silesia (spring 2026). The case turned partly on the reliability of a valuation expert. We demonstrated that the expert had applied a methodology inconsistent with the relevant Polish accounting standards, which the court accepted as grounds for ordering a supplementary opinion.

A party that disagrees with the final expert opinion must address it in closing submissions. Courts are not bound to follow expert opinions, but they rarely depart from them without a specific reasoned justification. Building that justification into your submissions – through technical counter-arguments, alternative methodologies, or procedural objections lodged earlier – is the only reliable strategy.

How do costs and timelines compare across three business scenarios?

Understanding the economics of expert evidence helps clients make informed decisions about when to push for an expert and when to resist one. Three scenarios illustrate the range of outcomes a dispute lawyer in Warsaw encounters regularly.

Scenario 1 – Manufacturing dispute (Silesia). A Polish manufacturer challenges a supplier's invoices for defective components. The court appoints a technical expert in materials engineering. The deposit is set at PLN 8,000. The opinion arrives in 60 days. Total expert costs, including supplementary written questions, reach PLN 12,000. The opinion confirms the defect, and the case settles within 90 days of the opinion being filed.

Scenario 2 – IT contract dispute (Warsaw). A Warsaw-based software company disputes a client's claim that delivered code failed to meet contractual specifications. An IT expert is appointed. The deposit is PLN 6,000. Delivery takes four months. The expert's opinion is contested on scope grounds; a supplementary opinion is ordered, adding three months and PLN 4,500 to the process. This scenario illustrates why precision in the original appointment order saves time and money.

Scenario 3 – Foreign investor (Mazowieckie). A German group challenges a Polish counterparty's valuation of a joint-venture asset. A financial expert is appointed. The deposit is PLN 20,000. The opinion takes six months. The investor's counsel submits detailed written objections referencing international valuation standards. The court orders a second expert, extending proceedings by a further eight months but ultimately producing a valuation closer to the investor's position. For cross-border matters, guidance on dispute resolution for Cyprus companies doing business in Poland illustrates analogous strategic considerations for foreign-held structures.

What are the most common mistakes parties make with expert evidence?

The complexity of expert proceedings in Poland creates predictable failure points. Awareness of these patterns is the first step toward avoiding them.

The most damaging mistake is passive engagement at the appointment stage. Parties that do not submit proposed questions before the appointment order is issued lose the ability to shape the expert's mandate. The court will proceed on the basis of the questions it formulates itself – which may not capture the nuances that determine liability or quantum.

A second common error is treating the deposit deadline as administrative rather than substantive. Under Polish procedural rules, failure to pay the deposit within the set period – typically 14 days – results in the court treating the expert appointment request as withdrawn. In disputes where expert evidence is essential to the claim, this can be catastrophic. For context on how employer-side cost discipline applies in related proceedings, see our analysis of minimum wage 2026 impact on employer costs in Poland.

Third, parties frequently underestimate the value of oral examination. Written objections are easier to prepare but less effective. An expert who has made an error in methodology is far more likely to concede under direct questioning at a hearing than in a written response, where they have time to rationalise their position.

  • Submit proposed questions before the appointment order is issued.
  • Pay the expert deposit within 14 days – treat it as a hard deadline.
  • Request oral examination rather than relying solely on written objections.
  • Frame any request for a second opinion around methodological error, not mere disagreement.

Sanctions compliance issues can arise in a cross-border context when the expert is asked to value assets connected to a sanctioned entity. In those cases, the expert's remit must be carefully delimited to avoid the opinion itself creating compliance exposure. This is an area where early coordination with specialist counsel pays dividends. For parallel considerations in enforcement proceedings, see our guide on enforcing a UAE judgment in Poland step by step.

Expert witnesses in arbitration Poland proceedings follow different rules. Institutional arbitration rules – such as those of the Sąd Arbitrażowy przy Krajowej Izbie Gospodarczej (Court of Arbitration at the Polish Chamber of Commerce) – give tribunals wider discretion over expert appointment and examination. Parties in arbitration should not assume that the KPC framework applies without modification.

What to prepare before expert proceedings begin:

  • A list of technical or factual questions you need the expert to address.
  • Credentials and conflict-of-interest information on any proposed expert.
  • Relevant technical standards, norms, or regulatory guidance applicable to the dispute.
  • Funds to cover the court-set deposit – budget at least PLN 5,000 to PLN 20,000 depending on complexity.
  • A procedural calendar noting the appointment order date and deposit deadline.

Your specific situation carries procedural consequences that cannot be undone once the appointment order is issued. Engaging specialist litigation counsel before that order is made – not after – is the only way to preserve all available options.

To receive an expert assessment of your position in Polish court proceedings involving expert witnesses, contact info@kordeckipartners.com.

Frequently asked questions

Q: How long does it typically take to receive an expert opinion in a Polish civil case?

A: Timelines vary significantly by subject matter. Simple valuations may take 30 to 45 days. Construction, engineering, or financial disputes regularly run three to six months, and supplementary opinions add further time. Parties should build these delays into their overall litigation timeline from the outset. Courts can impose financial penalties on experts who miss deadlines, but enforcement is inconsistent.

Q: Can a party appoint its own private expert rather than using a court-appointed one?

A: Yes. A party may submit a private expert opinion (opinia prywatna) as a document in evidence. However, Polish courts treat private opinions differently from court-appointed ones. A private opinion is assessed as a party's submission, not as independent expert evidence. It can be persuasive in framing the questions put to the court-appointed expert, but it does not carry the same procedural weight. Using a private opinion strategically – to challenge the court expert's methodology – is often more effective than relying on it as standalone proof.

Q: Is a KIO appeal procedure affected by expert evidence requirements?

A: KIO appeal proceedings before the National Appeals Chamber (Krajowa Izba Odwoławcza, KIO) follow a compressed timetable – decisions are typically issued within 15 days of the appeal being filed. The KIO may appoint an expert, but it does so rarely given the time constraints. Parties in public procurement disputes should front-load their technical arguments in the initial appeal submission rather than relying on expert appointment to develop them during the hearing.

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 dispute resolution. 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.