A Warsaw-based technology company is three months into commercial litigation when the opposing party submits a technical expert report that reframes the entire dispute. The client's legal team has fourteen days to respond. They do not yet have their own expert. That window closes – and with it, a significant opportunity to shape the court's factual findings.

Expert witnesses in Polish court proceedings are appointed by the court or proposed by the parties under the Kodeks postępowania cywilnego (Code of Civil Procedure, KPC). The court retains the final say on appointment, but parties may challenge an expert, submit written questions, and – critically – commission their own private opinions. Failing to engage with the expert phase proactively often forfeits the ability to contest unfavourable findings later.

This guide walks through the full expert witness procedure in Poland: how experts are appointed, how costs are allocated, what mistakes parties make, and how three common business scenarios play out in practice. It covers civil litigation, arbitration Poland settings, and procurement appeals before the National Appeals Chamber (KIO). Readers unfamiliar with Polish procedure will find jurisdiction markers and practical checkpoints throughout.

How are expert witnesses appointed in Polish civil proceedings?

Court-appointed experts in Poland come from a register maintained by each Regional Court (sąd okręgowy). The National Court Register (KRS) does not hold this list – it sits with individual courts. Appointment follows a formal court order, typically issued after the parties have exchanged pleadings and the factual scope is clear. The court defines the questions the expert must answer, and those questions bind the expert's mandate.

Parties have two routes to influence this process. First, they may request the appointment of a specific registered expert or an institution (a university faculty or a certified laboratory, for example). Second, they may submit proposed questions for the court to include in the appointment order. Both steps must be taken in the first substantive pleading or at the first hearing – delay risks the court treating the motion as time-barred under KPC procedural rules.

The expert has 30 days from receipt of the case file to submit a written opinion, though courts routinely grant extensions of 30 to 60 additional days in complex technical or financial matters. Once the opinion is filed, each party receives a copy and has 14 days to submit written objections or requests for supplementation. This is the single most important window in the expert phase. Missing it – or submitting vague objections – forecloses the ability to demand a supplementary opinion later.

  • Register of court experts: maintained by each Regional Court, not centrally
  • Appointment order: court defines the questions – parties should propose questions early
  • Initial opinion deadline: 30 days, extendable to 60–90 days in complex cases
  • Party objection window: 14 days from receipt of the expert's opinion
  • Institutional experts: universities, research institutes, and certified labs are eligible

One practical point that surprises foreign litigants: the Polish Financial Supervision Authority (KNF) and other regulatory bodies are sometimes asked to submit expert-type opinions in financial disputes. These carry significant weight but follow a different procedural track from registered court experts. Counsel should flag this distinction early when advising clients in regulated-sector litigation Warsaw proceedings.

What does the expert witness procedure cost – and who pays?

Expert fees in Polish civil proceedings are governed by the Minister of Justice regulation on expert remuneration. Fees are calculated on an hourly basis, with rates varying by specialisation. A financial or accounting expert typically charges between PLN 50 and PLN 150 per hour of documented work. A technical or engineering expert may reach PLN 200 per hour. Complex multi-volume opinions in construction or IP disputes can generate fees exceeding PLN 80,000 in a single proceeding.

The party that requests the expert appointment must advance a deposit to the court – usually PLN 2,000 to PLN 5,000 for a standard civil matter, higher for specialist fields. If neither party requests the expert and the court appoints one on its own motion, costs are initially borne by the court treasury and later allocated in the final judgment. The losing party generally bears all expert costs, including those advanced by the winning side.

Private opinions – commissioned outside the court process – are not court evidence in the formal sense. They are treated as the party's own argument. However, they carry real strategic value: a well-prepared private opinion shapes the questions the court asks the appointed expert, and it signals to the court that the party has substantive technical grounds for its position. We secured a favourable outcome for a manufacturing client in the Mazowieckie region (autumn 2025) by filing a private financial opinion before the court-appointed expert was even named, effectively setting the analytical framework the court adopted.

Cost allocation in arbitration Poland proceedings differs. Institutional rules of the Court of Arbitration at the Polish Chamber of Commerce (SA KIG) allow the tribunal to apportion expert costs based on the outcome of individual claims, not just the overall result. This gives parties more granular control over cost exposure when only some claims succeed.

What mistakes do parties make during the expert phase?

The most common mistake is passivity. Parties receive the expert opinion, disagree with its conclusions, but submit no written objections. Under KPC, a party that fails to object within 14 days is presumed to have accepted the opinion's factual findings. Courts do not automatically invite further comment. That silence becomes permanent record – and the appellate court will treat the findings as undisputed.

The second mistake is submitting objections that are too general. "The expert's methodology is incorrect" is not a valid objection in Polish procedure. Objections must be specific: identify the precise finding, cite the methodological flaw, and propose the corrective question for a supplementary opinion. Courts that receive vague objections routinely dismiss them without ordering supplementation. The dispute lawyer must frame objections as targeted questions the expert can actually answer.

The third mistake involves expert challenges. A party may challenge an expert on grounds of bias or conflict of interest – equivalent to the recusal mechanism for judges. The challenge must be filed before the expert submits the opinion. Filing after the opinion is delivered is procedurally too late in most circumstances. Foreign clients are often unaware of this deadline because it is not explicitly announced by the court.

For board liability and tax-related disputes – such as proceedings involving personal liability under Polish tax law – the expert phase frequently involves forensic accounting. Failing to commission a private forensic review before the court expert is appointed is a lost opportunity that cannot be fully recovered. For context on how board liability intersects with financial evidence requirements, see our analysis of board liability for tax arrears under the Tax Ordinance.

To discuss how your company's specific litigation position interacts with the expert phase – and the irreversible consequences of missing the 14-day objection window – contact info@kordeckipartners.com. Our disputes team in Warsaw and Krakow has handled expert challenges in proceedings ranging from PLN 500,000 to over PLN 50m.

How do the three business scenarios play out in practice?

Manufacturing disputes in Poland typically involve construction defects, product liability, or supply chain failures. The expert phase in these cases is long – 6 to 12 months is common when site inspections, laboratory testing, and multi-party coordination are required. The key strategic decision is whether to appoint a single joint expert (saving time and cost) or to allow each party's position to be tested by separate opinions. Courts in Silesia and Małopolska have shown a preference for institutional experts (university technical faculties) in large-scale construction disputes, which adds credibility but extends the timeline by 60 to 90 days.

IT and technology disputes present a different challenge. Source code review, software valuation, and cybersecurity assessments require specialists who are rarely on regional court expert registers. Parties often need to apply to appoint an expert from outside the register – a process requiring court approval and, sometimes, KNF input in regulated fintech matters. We obtained interim measures protecting assets worth over EUR 3m for a technology client in Lower Silesia (spring 2026) by moving quickly on the expert appointment before the opposing party could contest the scope of the court's questions.

Foreign investors face an additional layer. A German or Dutch investor engaged in Polish litigation may be unfamiliar with the distinction between a court-appointed expert and a private opinion. Both serve different functions. The court expert determines the facts. The private opinion shapes the questions. Investors who treat these as interchangeable – filing a private report in response to a court expert's findings without also submitting formal objections – lose the procedural opportunity entirely. For Netherlands-based investors, our guide on dispute resolution for Netherlands companies doing business in Poland addresses this distinction in detail.

KIO appeal proceedings – challenges to public procurement decisions before the National Appeals Chamber – operate under a compressed timeline. The KIO must issue a ruling within 15 days of the appeal being filed. Expert evidence in KIO proceedings is rare but decisive when it appears: a technical expert opinion on whether a tender specification was discriminatory can determine the entire outcome. Parties should prepare expert support before filing the appeal, not after.

What is the procedure for cross-border and enforcement scenarios?

Cross-border disputes add procedural complexity to the expert phase. When a party seeks to enforce a foreign judgment in Poland – or when Polish proceedings involve foreign-law questions – the court may appoint an expert in foreign law. This is distinct from a factual expert. A foreign-law expert advises the court on the content of another jurisdiction's legal rules. The appointment follows the same 30-day default timeline, but sourcing a qualified expert in, say, Ukrainian commercial law can extend preparation by 45 to 60 days.

Sanctions compliance questions are increasingly appearing in Polish commercial disputes. A counterparty's alleged breach of EU sanctions regulations may be a factual matter requiring expert evidence on transaction monitoring, beneficial ownership, or payment routing. These experts are not on standard court registers. Parties must apply for ad hoc appointment. The court's discretion is wide, and the application should be supported by a private preliminary opinion demonstrating that the question is genuinely technical rather than purely legal.

For parties enforcing Ukrainian judgments in Poland – a growing category since 2022 – the expert phase may arise in the recognition proceedings themselves, particularly where the Ukrainian judgment involved a factual determination that the Polish court wishes to verify independently. Our step-by-step guide on enforcing a Ukraine judgment in Poland covers how expert evidence interacts with the recognition procedure under the Hague Convention framework.

Arbitration Poland proceedings before SA KIG or the Vienna International Arbitral Centre (VIAC) allow parties considerably more flexibility. The tribunal may appoint a single expert, allow each party to present its own expert witness in a "hot-tubbing" format, or rely on written reports only. This flexibility is an advantage – but it requires early agreement in the procedural timetable. Leaving the expert question unresolved until the first hearing wastes 60 to 90 days and risks a tribunal-imposed solution that neither party controls.

Specific figures matter here. In international arbitration proceedings seated in Poland, expert fees regularly exceed EUR 20,000 for financial matters and EUR 50,000 for complex engineering disputes. Budgeting for the expert phase from the outset – not as an afterthought – is a marker of experienced litigation management.

For a tailored strategy on managing the expert phase in your cross-border dispute, reach out to info@kordeckipartners.com. Our team handles matters from initial pleadings through enforcement, including cases involving sanctions compliance and foreign-law questions.

What should you prepare before the expert phase begins?

Preparation before the expert phase starts is the single greatest lever a party has. Once the court appoints an expert and defines the questions, the scope is largely fixed. Parties who wait until the opinion arrives are already reacting rather than shaping. The following checklist applies across civil litigation, arbitration Poland, and KIO appeal proceedings.

  • Identify the technical or financial questions at the core of your case – before filing the claim or defence
  • Commission a private preliminary opinion to test your position and identify gaps
  • Prepare proposed expert questions in writing and include them in your first substantive pleading
  • Research available registered experts in the relevant Regional Court and assess potential conflicts
  • Budget for expert costs: advance deposit of PLN 2,000–5,000 minimum, plus potential final allocation of PLN 20,000–80,000+

The decision matrix is straightforward. If your dispute turns on a technical fact – causation, valuation, standard of care – you need expert support before the hearing, not during it. If the dispute is primarily legal, expert evidence may be unnecessary. If it is both (as in most complex commercial cases), the private opinion should address the factual layer while counsel handles the legal arguments. Mixing the two in a single document – legal argument dressed as expert opinion – is a mistake courts notice immediately.

Three business scenarios illustrate the matrix. A manufacturing company disputing a PLN 5m construction defect claim should commission a technical expert before filing, propose questions in the statement of claim, and budget 9 to 12 months for the expert phase. An IT company contesting a software licence termination should prepare a private source-code review and apply for an out-of-register expert appointment. A foreign investor challenging a procurement decision before the KIO should have expert support ready before the 15-day window opens.

Frequently asked questions

Q: Can a party request a second expert opinion if it disagrees with the first?

A: Yes, but the threshold is procedural, not simply disagreement. The party must demonstrate in its written objections that the first opinion contains a specific methodological error, internal inconsistency, or relies on incomplete data. The court then decides whether to order a supplementary opinion from the same expert or appoint a new one. Simply finding the conclusions unfavourable is not sufficient grounds. Courts in Poland treat repeated expert appointments with scepticism, and a second appointment typically adds 3 to 6 months to the proceedings.

Q: How long does the full expert phase take in a typical commercial dispute?

A: In straightforward financial disputes before a Warsaw district court, the expert phase – from appointment order to final opinion accepted by the court – typically takes 4 to 7 months. Complex technical matters, multi-party construction disputes, or cases requiring institutional experts (university faculties) regularly extend to 12 to 18 months. Arbitration proceedings under SA KIG rules can compress this to 3 to 5 months if the procedural timetable is agreed early. Budget for the longer end of any range when managing client expectations.

Q: Is a private expert opinion admissible as evidence in Polish court proceedings?

A: Not as formal expert evidence in the procedural sense. Under the Code of Civil Procedure, only court-appointed experts produce evidence that binds the court's factual findings. A private opinion is treated as the party's own submission – essentially a sophisticated legal argument supported by technical analysis. However, it has real practical value: it shapes the questions put to the court expert, flags methodological issues in advance, and signals to the court that the party has substantive grounds for its position. Courts that receive well-prepared private opinions before appointing their own expert tend to ask sharper, more targeted questions.

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 on matters ranging from KIO procurement appeals to cross-border enforcement 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.