Paternity — Establishment and Challenge — Legal Assistance in Poznań
Paternity cases are ones in which law and emotion become entangled with unusual intensity. They touch on a child’s identity, family relationships and the obligations that flow from parenthood — maintenance, inheritance, parental authority. We assist both those seeking to challenge the presumption of paternity and those pursuing its judicial establishment.
Tel.: +48 531 335 713 | kancelaria@prawnikodrozwodu.pl
Challenging Paternity
What Does It Involve?
Where a child is born during a marriage, or within 300 days of its dissolution or annulment, Polish law presumes that the mother’s husband is the child’s father (Art. 62 of the Family and Guardianship Code, Kodeks rodzinny i opiekuńczy, k.r.o.). This is a legal presumption — it operates automatically, regardless of the biological reality. Challenging paternity (zaprzeczenie ojcostwa) is the court proceedings by which that presumption is rebutted.
Who Can Bring a Claim?
A claim to challenge paternity may be brought by the mother’s husband, the mother, the child after reaching the age of majority, or the public prosecutor where the child’s welfare or the public interest so requires.
Time Limits — This Is Critical
Paternity challenge proceedings are subject to strict time limits. Once they expire, the door to court is closed.
The mother’s husband has one year from the day he learned that the child is not his biological child — but no later than the child’s eighteenth birthday (Art. 63 k.r.o.). The mother also has one year, running from the day she learned that the child is not her husband’s — and likewise no later than the child’s eighteenth birthday (Art. 69 k.r.o.). The child has one year from the day they learned they are not the biological child of their mother’s husband (Art. 70 k.r.o.).
These are limitation periods of a strict kind (terminy zawite) — once they have expired, the court will dismiss the claim regardless of the circumstances. If you have doubts about paternity, do not delay in seeking advice.
Legal Consequences
A final judgment challenging paternity extinguishes the legal relationship of kinship between the child and the man previously regarded as the father. Parental authority ceases, and mutual rights and obligations — including the maintenance obligation and inheritance rights — come to an end. This is a permanent and far-reaching change for everyone involved.
Establishing Paternity
When Is It Necessary?
Establishing paternity is required where a child was born outside marriage and the presumption of paternity does not apply — or where it has been rebutted in prior proceedings.
Two Routes: Acknowledgment and Court Proceedings
Acknowledgment of paternity (uznanie ojcostwa) is the simpler and faster option where the father is known and willing to voluntarily confirm his paternity. It is done by making a declaration before the head of the civil registry office (kierownik Urzędu Stanu Cywilnego), the family court or a consul — it requires confirmation by the mother (Art. 73 k.r.o.). No court proceedings are necessary.
Judicial establishment of paternity is required where the man disputes paternity or is unwilling to acknowledge it voluntarily. The court applies the presumption in Art. 85 k.r.o. — the father is the man who had sexual relations with the mother no earlier than 300 and no later than 181 days before the birth. In practice, the key evidence is a DNA test, which can establish biological paternity with near-certainty.
Who Can Bring a Claim?
A petition for judicial establishment of paternity may be filed by the child after reaching the age of majority, by the mother — until the child turns 18, by the putative father — also until the child turns 18, and by the public prosecutor where the child’s welfare or the public interest so requires (Art. 84 k.r.o.).
Legal Consequences of Establishing Paternity
A judgment establishing paternity creates a full legal relationship between the father and the child: parental authority arises, the maintenance obligation comes into existence, inheritance rights and obligations are established, and the child acquires the right to bear the father’s surname. This is not a formality — it is a change that shapes the child’s legal position for life.
How Do the Proceedings Work?
Both paternity challenge and paternity establishment cases are heard by the district court (sąd rejonowy) with jurisdiction over the child’s place of residence. In Poznań these are the District Courts of Poznań-Stare Miasto, Poznań-Nowe Miasto and Wilda, and Poznań-Grunwald and Jeżyce.
During proceedings the court takes evidence — most commonly a DNA test (applied for by a party or ordered by the court of its own motion), witness evidence and the examination of the parties. DNA testing is now standard and produces results of near-100% reliability. If a party refuses to submit to testing, the court may draw adverse inferences from that refusal.
The duration of proceedings depends on whether the case is contested and whether DNA testing is required. Uncontested cases where the parties cooperate may conclude within a few months. Contested proceedings involving expert evidence typically last one to two years.
Why Have a Lawyer in a Paternity Case?
At first glance these cases can appear straightforward — there is a DNA test, there is a result, there is a judgment. In practice it is often more complex.
The most important issue is time limits. Both paternity challenge and establishment proceedings are subject to strict limitation periods. Once they have expired, the court will dismiss the claim without examining its merits. The difficulty is that the period runs from the day the party learned of the relevant circumstances — and establishing that date is often disputed and may be the subject of a procedural objection by the other side. A lawyer will assess whether the period is still running and advise on how to justify the date of discovery in a way that withstands challenge.
The second issue is the scope of the judgment’s effects. A judgment establishing or challenging paternity changes the child’s legal position in several areas simultaneously — maintenance, inheritance, parental authority, surname. It is worth knowing in advance what consequences the judgment will carry, and whether related matters should be dealt with before the proceedings conclude.
The third issue is contested cases. If the putative father denies paternity and refuses to submit to DNA testing, or if the mother obstructs access to the child or to documents, the proceedings require active representation. This is not a case where filing a petition and waiting is sufficient.
Finally — the emotional dimension. Paternity cases rarely unfold in a calm atmosphere. They touch on matters that are deeply personal for everyone involved. A lawyer not only conducts the proceedings but also helps maintain perspective and avoid taking procedural decisions under the influence of emotion.
Frequently Asked Questions
Is DNA testing compulsory? It is not compulsory, but in practice it is the most important piece of evidence in paternity cases. If a party refuses to submit to testing, the court may draw adverse inferences from that refusal. A DNA test can establish biological paternity with an accuracy exceeding 99.99%.
What if the mother refuses to confirm acknowledgment of paternity? Acknowledgment of paternity requires the mother’s confirmation. If she refuses, the only available route is judicial establishment of paternity.
Can paternity be challenged if the child is already a teenager? Yes, provided the strict time limit has not expired. The mother’s husband has one year from the day he learned that the child is not his biological child — regardless of the child’s age, but no later than the child’s eighteenth birthday.
What are the costs of proceedings? The court filing fee for a paternity challenge or establishment petition is 200 PLN. There may also be costs for DNA testing — typically several hundred PLN depending on the laboratory — and legal fees, which are agreed individually.
Contact Us
Paternity cases have serious legal and personal consequences — for the child, the parents and the whole family. We practise in Poznań and across Greater Poland, including Jarocin, Kalisz, Ostrów Wielkopolski, Pleszew and Gostyń.
Kancelaria Prawa Rodzinnego Adwokat Michalina Koligot, Adwokat Marta Krzyżanowicz, Adwokat Anna Konrady, Radca Prawny Joanna Jędrzejewska
ul. Mickiewicza 18a/3, 60-834 Poznań Tel.: +48 531 335 713 kancelaria@prawnikodrozwodu.pl | prawnikodrozwodu.pl
Office hours: Monday–Friday, 8:00–16:00 Consultations in person and online. First consultation: 400 PLN.
This page is for general informational purposes only and does not constitute legal advice. Legal information current as of January 2026.