Does infidelity automatically mean fault in a Polish divorce?

Infidelity is one of the most common reasons cited in Polish divorce proceedings. Many people assume that if a spouse was unfaithful, the case is straightforward – the court will find them solely at fault for the breakdown of the marriage, and that will be that. The reality is more nuanced. Yes, infidelity is a serious breach of marital obligations under Polish law. But no, it does not automatically lead to a finding of sole fault – and the court does not assess infidelity in isolation from the full history of the marriage.

Table of contents

1. The duty of fidelity – what does Polish law say?
2. Infidelity and fault in divorce proceedings – the rule and its limits
3. When does infidelity not determine sole fault?
4. What must the spouse relying on infidelity prove?
5. Practical consequences of a fault finding
6. FAQ

The duty of fidelity – what does Polish law say?

Marital fidelity in Poland is not merely a moral expectation – it is a legal obligation. Article 23 of the Family and Guardianship Code (Kodeks rodzinny i opiekuńczy) provides that spouses are required to cohabit, to support each other, and to remain faithful. The Supreme Court (Sąd Najwyższy), in its judgment reference II CKN 220/98, confirmed that fidelity is one of the fundamental duties of marriage.

Importantly, this obligation is absolute in character. As the Supreme Court held in an earlier judgment, reference II C 1255/53: “The duty of fidelity is not subject to the parties’ agreement, and therefore adultery constitutes a ground for the breakdown of marital cohabitation even where it occurred with the consent of the other spouse.” In other words, even where spouses have agreed to an open relationship, this does not automatically eliminate the legal significance of infidelity under Polish law.

Infidelity and fault in divorce proceedings – the rule and its limits

The fault determination in divorce proceedings is governed by Article 57 of the Family and Guardianship Code. The court establishes which spouse bears fault for the complete and permanent breakdown of the marriage. It may find one spouse solely at fault, find both spouses at fault, or – where both parties so request – refrain from making any fault determination at all.

Infidelity is among the most frequently cited causes of marital breakdown and in many cases does indeed result in the unfaithful spouse being found solely at fault. But the law does not operate mechanically. The mere fact of infidelity is not sufficient – the court examines whether the infidelity caused the breakdown of the marriage, or whether the marriage had already broken down before the infidelity occurred, with the infidelity following as a consequence.

When does infidelity not determine sole fault?

This is the aspect that most often surprises people unfamiliar with how Polish divorce law works in practice. The Regional Court (Sąd Okręgowy) in Świdnica, in its judgment reference I C 837/16, articulated the principle clearly:

“In the relationship between the cause – here, a breach of marital obligations – and the effect, namely the complete and permanent breakdown of cohabitation, the cause must obviously precede the effect. If the breakdown has already occurred, no subsequent failure to fulfil marital obligations can be characterised as a cause of that breakdown. For this reason, the defendant’s entering into a relationship with another partner during the marriage, but after the date on which the complete and permanent breakdown of cohabitation between the spouses had already taken place, does not provide grounds for treating the defendant’s conduct as a deliberate act of hostility towards the claimant.”

The Supreme Court expressed the same view in its judgment reference III CKN 128/98, holding that a spouse entering into a new relationship during the marriage but after its complete and permanent breakdown does not thereby become solely at fault for that breakdown.

Put plainly: if the marriage had factually ended before the infidelity occurred – the parties were living separately, maintaining no emotional or physical relationship, leading entirely independent lives – and only after that point did one spouse become involved with someone new, the court may find that the infidelity was not the cause of the breakdown but its consequence. An effect cannot simultaneously be a cause.

What must the spouse relying on infidelity prove?

A party seeking to have infidelity recognised as the cause of marital breakdown must establish two things. First, that the infidelity actually occurred – typically through witness testimony, correspondence, photographs, or other documentary evidence. Second, and this is often the harder task, that the infidelity took place before the complete and permanent breakdown of the marriage, not after it.

The spouse accused of infidelity may defend themselves by demonstrating that the new relationship began only after the marriage had in fact ceased to exist – the parties were no longer living together, no longer communicating, no longer connected by any meaningful bond. In our experience, the chronology is decisive: the dates of physical separation, correspondence between the parties, witness testimony confirming the earlier breakdown – these are the elements that can entirely change the court’s assessment of the situation.

Practical consequences of a fault finding

A finding of sole fault carries real legal consequences, which is why both parties frequently contest this issue vigorously.

The most significant consequence concerns spousal maintenance (alimenty między małżonkami). Under Article 60 § 2 of the Family and Guardianship Code, an innocent spouse who suffers a significant deterioration in their standard of living as a result of the divorce may claim maintenance from the spouse found solely at fault – even where the innocent spouse is not in actual need. This is a considerably broader entitlement than applies where both spouses are found to share fault, or where the court makes no fault finding at all.

A fault finding also affects the overall character of the proceedings. Cases involving a fault determination tend to take longer, generate greater conflict between the parties, and involve higher legal costs. Many couples choose to divorce without a fault determination precisely because they want to bring the matter to a close quickly and without further escalation.

FAQ

Is infidelity alone sufficient for the court to find a spouse solely at fault? Not automatically. The court assesses whether the infidelity was the cause of the marital breakdown, or whether it occurred after the marriage had already completely and permanently broken down. If the marriage had in fact ended before the infidelity, the infidelity cannot be treated as its cause.

How is infidelity proved in Polish divorce proceedings? Most commonly through witness testimony, printed or screenshot correspondence, photographs, or other documents. It is worth noting that evidence obtained in a way that infringes on the other party’s privacy may be disregarded by the court or assessed critically. It is advisable to discuss with a lawyer which evidence is admissible in the specific circumstances of your case.

Does the other spouse’s consent to infidelity protect against a fault finding? No. The Supreme Court held in judgment reference II C 1255/53 that the duty of fidelity is not subject to the parties’ agreement – even the other spouse’s consent does not eliminate the legal breach. Consent may, however, be taken into account by the court as part of its overall assessment of the circumstances.

Can a spouse who was also unfaithful successfully rely on the other’s infidelity? Yes, but the court will consider the conduct of both spouses. Where both have breached the duty of fidelity, the likely outcome is a finding of shared fault rather than sole fault on one side.

Is it worth seeking a fault finding if your spouse was unfaithful? It depends on the individual circumstances – principally on whether the innocent spouse stands to benefit from the broader maintenance entitlement that follows a sole fault finding, and whether they are prepared for longer and more adversarial proceedings. Every case requires individual assessment.

I am a foreign national – does fault matter the same way in Polish law as in my home country? Fault in divorce is a distinctly Polish legal concept and operates differently from many other legal systems, particularly those that have moved to purely no-fault divorce. In Poland, a fault finding has concrete financial consequences, primarily regarding spousal maintenance. If you are used to a system where fault is either irrelevant or handled differently, it is worth understanding these specifics before deciding how to approach your case.

Wondering how infidelity might affect your divorce proceedings in Poland? Call: +48 531 335 713 or email: kancelaria@prawnikodrozwodu.pl

This article is for general informational purposes only and does not constitute legal advice. Every family law case is individual and requires analysis of the specific facts and documents involved. The law firm accepts no liability for actions taken on the basis of the information contained in this article. For advice tailored to your situation, please contact our office.

Kancelaria Prawa Rodzinnego (Family Law Office): 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 | www.prawnikodrozwodu.pl