Challenging a Polish Will: When It's Possible and How to Do It

Legal notice: This guide is general legal information, not legal advice. How the rules apply depends on your individual circumstances, and the matter should be assessed by a qualified Polish lawyer. Twoja Sprawa helps you organise the documents for that assessment.

A will can be neatly written and still not be valid. If you suspect a will was forged, made under duress, or written by someone who did not understand what they were doing, you have the right to challenge it in a Polish court. This guide explains when a will can be invalidated and how to go about it.

When is a will invalid? Grounds for invalidity

Invalidity of a will falls into two categories: formal invalidity and substantive invalidity.

Formal invalidity — defects in the form of the will

A will is formally invalid if it fails to meet the requirements set out in Articles 949–951 of the Polish Civil Code (Kodeks cywilny, "KC"). Examples include:

• No handwriting — a will printed from a computer rather than written by hand
• No date — a will missing the day, month, and year
• No signature — a will not signed by the testator
• A printed fragment — even one part of the will being typed rather than handwritten
• A joint will — two people writing a will together (prohibited under Article 943 KC)

For formal invalidity, it is enough for an heir who is unhappy with the will to show that one of the required elements is missing. The court will automatically treat the will as invalid — no further evidence is needed.

Substantive invalidity — defects of intent (Article 945 KC)

A will can be formally correct (properly written) but substantively invalid because of a defect of intent. Article 945 KC lists these grounds:

1. Mistake — the testator made an error while writing the will; for example, they meant to write "my son John" but wrote "my son Peter" by genuine mistake
2. Threat (duress) — the testator wrote the will under coercion, threat, or blackmail
3. Lack of capacity — the testator was not aware of what they were doing; they were writing while intoxicated, under anaesthesia, suffering from mental illness, or affected by severe dementia
4. Fraud — the will was forged, or the date, signature, or entire document was fabricated

Each of these grounds requires evidence — simply asserting a defect is not enough. You must prove to the court that it genuinely occurred.

How to prove a defect of intent — the burden of proof

The burden of proof rests on the person challenging the will. This means you must prove to the court that, for example:

• The testator was under duress (witnesses, letters, messages, testimony)
• The testator had dementia (a forensic medical opinion, medical records, testimony from relatives)
• The will was forged (handwriting analysis, expert testimony)
• The testator was intoxicated or unconscious (medical records)

Example: Your grandmother wrote a will leaving her entire estate to a third party — the carer who looked after her. You suspect she was pressured into it. To invalidate the will, you would need to gather:

• Witness statements that the carer was putting pressure on your grandmother
• Medical records on your grandmother's mental state at the relevant time
• Letters, emails, recorded conversations
• Handwriting expert evidence (if you suspect the signature was forged)

Without such evidence, the court will dismiss the claim.

The time limit for bringing a claim (limitation period)

⚠️ Important: a claim to have a will declared invalid is subject to a limitation period. Under Article 969 KC, the time limit is:

• 3 years from becoming aware of the ground for invalidity,
• but no later than 10 years from the opening of the estate (the testator's death)

What does this mean in practice? If the testator died on 1 June 2020 and it is now June 2026, you would still have roughly 4 years left to sue for invalidity (until June 2030). But if you only found out about the duress in 2024, the clock starts running from 2024 — you would have 3 years from that point.

Don't delay. If you suspect a defect in a will, you should consult a lawyer as soon as possible.

Can a notarial will also be challenged?

Yes, but it is much harder. A notarial will (a will made before a notariusz — a civil-law notary in Poland, not a UK notary public — and recorded as a notarial deed, akt notarialny) carries significant evidential weight, because the notary formally records the testator's identity, capacity, and apparent awareness at the time. To challenge a notarial will, you would need very strong evidence of:

• Falsification of the notarial record (in practice almost impossible, since notarial documents are securely protected)
• Dementia or lack of awareness on the testator's part at the moment the will was made, even though the notary recorded that the testator appeared lucid (this requires a medical opinion)
• Duress that the notary failed to notice (this requires credible witnesses)

In practice, a notarial will is very difficult to overturn unless you have compelling evidence. This is one of the reasons a notarial will is considered the safer option.

Where and how to bring a claim to invalidate a will

1. Which court: The claim is brought before the district court (sąd rejonowy) covering the testator's last habitual place of residence — i.e. where they were living at the time of death.

2. Form of the claim: The claim must be filed in writing and should include: - The names and addresses of the parties - Identification of the will in question (date, notary, or place where it is held) - A description of the grounds for invalidity (Article 945 KC) - Evidence supporting your position - The relief sought (e.g. "the claimant seeks a declaration that the will dated [X] is invalid")

3. Legal representative: If you live in the UK, you can instruct an adwokat or radca prawny (Polish advocate or legal counsel) to bring the claim on your behalf in Poland. A legal representative will file the claim and appear at hearings on your behalf — you generally do not need to attend in person.

4. Court fee: This depends on the value of the estate in dispute; as a rough guide, expect anything from a few hundred to several thousand PLN.

Was the testator deceived — a forged signature

If you suspect that the signature on the will is forged, this is grounds for complete invalidity (Article 945 KC, a defect relating to authenticity).

To prove this:

1. A forensic handwriting expert — ask the court to appoint an expert to analyse the handwriting and compare the signature on the will with authentic signatures (cheques, contracts previously signed by the testator)
2. Cost of the expert opinion — this is usually borne by the claimant initially, but if the claim succeeds, they may seek reimbursement of the cost
3. Application to reopen proceedings — if the will has already been acted on (heirs have divided the estate), you may be able to apply to reopen proceedings on the basis of new evidence

What if the testator had dementia — a medical opinion

If your argument is that the testator had dementia, severe cognitive decline, or another mental illness at the time the will was made:

1. Gather medical records — hospital discharge summaries, prescriptions for psychotropic medication, medical reports from the relevant period
2. Statements from relatives — witnesses who saw the testator regularly and can confirm they had cognitive difficulties
3. A forensic medical opinion — you can apply for the court to appoint a psychiatric expert to assess, based on the documents, whether the testator was capable of understanding what they were doing

⚠️ Difficulty: dementia needs to be proven to the court's evidential standard — informal impressions that "grandma was forgetful" are unlikely to be enough on their own.

Frequently asked questions

Can I challenge a will if I believe the testator lacked capacity? Yes, provided you can prove it. You will need to gather medical records and apply for a forensic medical expert to be appointed. The burden of proof is on you.

Can a notarial will be forged? In practice, almost never. A notarial will is held by the notary, so forgery would be extremely difficult and easy to detect. If you believe the notary did something improper, you may be able to bring a separate claim against them, but that is a different matter.

What is the time limit to challenge a will? Three years from becoming aware of the ground for invalidity, but no later than 10 years from the testator's death. If the testator died 10 years ago and you only found out yesterday that the will is fraudulent, you may already be out of time.

Can I challenge a will myself, without a lawyer? Technically yes, but this is not recommended. Polish civil procedure is complex, and evidence has to be gathered and presented correctly. Without a lawyer, you risk having the claim dismissed on procedural grounds alone.

What if the testator was under the influence of drugs or alcohol? If the testator wrote the will while intoxicated, the will can be invalidated under Article 945 KC (lack of capacity). You would need to prove this with witnesses, medical records, and statements from people who were present at the time.

Legal basis and sources

• Article 945 KC — defects of intent
• Article 969 KC — limitation period for claims to have a will declared invalid
• Articles 949–951 KC — formal requirements for wills
• Case law of the Polish Supreme Court on the invalidity of wills (available via CBOSA)