How to Write a Will
The Most Common Mistakes and How To Avoid Them
A will is a key legal document, yet people often draft it incorrectly. Unclear identification of an heir, a missing witness signature, a vague description of assets, or an incorrect form may render it invalid. The result is legal disputes, delays in probate proceedings, and loss of assets. This article will guide you through the most common mistakes and show you how to eliminate them so that your last will is legally valid and enforceable.

The most common cause of a will being invalid is formal errors:
- a missing signature, an incorrect number of witnesses, unclear details about the heir, or the date of execution.
- Vague or indefinite expressions of intent (for example, “to leave the cottage to my grandson” without precise identification of the property) lead to interpretative disputes and potential invalidity of parts of the will.
- Failure to respect the rights of forced heirs (descendants) may result in relative invalidity and the need to pay mandatory shares.
The safest approach is therefore to execute a will in the form of a notarial deed, which automatically eliminates formal risks.
Formal requirements for a will: Where mistakes are most commonly made
Czech legislation (specifically Act No. 89/2012 Coll., the Civil Code, hereinafter the “Civil Code”) recognises three basic forms of a will: a handwritten (holographic) will, a non-handwritten (allographic) will, and a will executed in the form of a notarial deed. Each form has specific requirements, and breaching them leads to absolute invalidity—i.e., a situation where the will is treated as if it never existed.
Holographic will: When it may not be sufficient
A handwritten will must be written entirely by the testator in their own hand and signed by them personally (Section 1533 of the Civil Code). A typical mistake is when someone prints the will on a computer and only signs it by hand. A will prepared in this way is absolutely invalid.
The reason is that the law requires the entire text to be handwritten—it is not enough to merely sign a printed document.
Another common mistake is the absence of a date. Although this does not in itself cause absolute invalidity of the will if the date can be proven by other means (Section 1535(1) of the Civil Code), failing to state it—or stating it incorrectly—is a major risk. If the testator left multiple wills that contradict each other and it is not clear which was executed later, all of them may be considered invalid or serious interpretative disputes may arise. A later will revokes the earlier one, but only if it is clear which is newer. Without a date, legal uncertainty—or even a loss of rights—may occur. The date should therefore always be stated and must be truthful.
Allographic will and the role of witnesses: The most common procedural mistakes
If a will is not written in the testator’s own hand (for example, on a computer, on a typewriter, or by another person), it is an allographic will (Section 1534 of the Civil Code). The requirements here are stricter: the testator must sign the will personally and do so in the presence of two witnesses who are present at the same time. The key word is at the same time. The witnesses must not be present “one after another”—it must be apparent to both that the testator is expressing their last will.
A typical mistake: the testator prepares an allographic will, signs it, but forgets to declare in front of the witnesses that the document contains their last will. A signature alone is not sufficient. The law expressly requires the testator to declare aloud before the witnesses that the document contains their last will (Section 1534(2) of the Civil Code). Omitting this formality without justification leads to absolute invalidity.
Another issue is the selection of witnesses (Section 1536 of the Civil Code). A witness cannot be a person who is an heir under the will, nor a person close to them. A “close person” is defined in Section 22 of the Civil Code and includes, for example, a husband/wife, partner, a relative in the direct line, a sibling, or a person in a similar relationship (e.g., a cohabiting partner).
Likewise, an employee of an heir cannot act as a witness. The reason is the prevention of conflicts of interest—the witness must not derive any benefit from the content of the will.
Statutory exclusions:
- Anyone who does not have full legal capacity.
- Anyone who is blind, deaf, or mute.
- Anyone who is an heir or a legatee (a beneficiary of a legacy; see Section 1594 of the Civil Code).
- Anyone who is a close person to an heir or a legatee.
- Anyone who is an employee of an heir or a legatee, or an employee of a close person to an heir or a legatee.
If, for example, the witness were the future heiress or her husband, the will would not meet the statutory form requirements and would be invalid.
Date and identification of the testator: Details that are often overlooked
A will should always clearly state who is making it (identification of the testator by first name and surname, personal identification number or date of birth, and address). Although this may seem obvious, in practice we encounter partially illegible names or inaccurate details. If there is uncertainty as to who the true author of the will is, the will may become invalid or at least difficult to enforce.
Unclear identification of heirs and assets: A source of future disputes
A will must contain a clear and definite expression of the testator’s intent. This means the intent must be stated with certainty—mere assent or vague wording is not enough. A large number of mistakes are made here, which then lead to interpretative disputes in probate proceedings and sometimes even to partial invalidity.
Vague designation of an heir
The testator has two sons, for example Jan and David. In the will, he writes: “I leave my apartment to my son.” What is the result? Uncertainty as to which heir is entitled.
Similarly problematic is the wording: “My children inherit equally”—but if the deceased left children and grandchildren and some of the original children have already died, the question arises as to how to correctly interpret the shares of the grandchildren versus the living children under the statutory order of succession, unless expressly stated otherwise.
Properly, each heir should be unambiguously identified by first name, surname, and ideally also date of birth and address. An example of good practice: “To my son Jan Nováček, born on 1 January 1980, residing in Prague, Karlínská 123, I leave apartment no. 45 in Prague.” This eliminates doubts and at the same time reduces the scope for court disputes.
Indefinite description of assets
Equally risky is when the testator writes: “I leave the cottage in the mountains to my niece” or “I leave the model car to my grandchild.” Where exactly is that cottage located? Which bed? If the estate includes multiple cottages or multiple model cars, ambiguity arises.
Correct approach: Provide precise identification of the real estate (address, plot number, building registration number/record number, cadastral area, title deed number); for movable assets, provide specific identification (vehicle VIN, license plate number, specific description, production or serial number for paintings, jewellery, etc.). The more precise the description, the lower the risk of a dispute and partial invalidity.
Issue with forced heirs: When the law limits your decision-making
Czech law recognises the concept of forced heirs (Section 1642 of the Czech Civil Code) – these are primarily your descendants (children, and if they do not inherit, then their descendants). These heirs have a statutory right to a compulsory share of the estate, which they cannot be deprived of even by a will, unless they have been validly disinherited.
What is the amount of the compulsory share?
- Minor descendant : at least three quarters of their statutory inheritance share.
- Adult descendant : at least one quarter of their statutory inheritance share.
This means that if you want to leave your assets only to your spouse and omit your descendants, the descendants may claim their compulsory share. If the will absolutely denies this right (e.g., “I do not call my children to inherit at all”), relative invalidity of the will arises within the meaning of Section 1546 of the Czech Civil Code – under certain conditions it becomes enforceable only in part (to the extent of the compulsory share).
Grounds for disinheritance: Exceptions to the rule
However, exceptions exist. The testator may disinherit a descendant if the statutory grounds are met:
- The descendant failed to provide the testator with necessary assistance in distress, although they had a duty to do so and could have done so.
- The descendant shows no genuine lasting interest in the testator that they should show as a descendant.
- The descendant was convicted of an intentional criminal offence committed under circumstances indicating their depraved character.
- The descendant leads a persistently dissolute life.
- The descendant is so indebted or acts so wastefully that there is a serious risk that the compulsory share that would fall to their descendants (i.e., the testator’s grandchildren) would not be preserved.
However, disinheritance must be explicit and fact-specific in the will (in a deed of disinheritance). An indefinite or vague explanation (“I do not want them to inherit because...”) may not be legally sufficient.
This is where there is full scope for the lawyers at ARROWS advokátní kancelář – they will professionally help you formulate disinheritance in a way that will stand up in court without contradiction. A deed of disinheritance is subject to the same formal requirements as a will.
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Potential issues |
How ARROWS can help (consultation@arws.cz) |
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Invalid form: The will is absolutely invalid and has no legal effects. |
The attorneys of ARROWS, a Prague-based law firm, will help you prepare a will so that it safely meets all formal requirements. In the event of a dispute over validity, they will represent you in court proceedings in the Czech Republic. |
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Unclear expression of intent: This leads to court disputes, partial invalidity, and lengthy proceedings. |
ARROWS, a Prague-based law firm, will review your will and ensure a linguistically and legally precise wording that eliminates interpretative disputes. |
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Infringement of the rights of forced heirs: The court will order you to pay the mandatory share, whether you like it or not. Without the right legal strategy, costly litigation may follow. |
The attorneys at ARROWS, a Prague-based law firm, will help you find a solution compliant with Czech law—whether this involves disinheritance or an appropriate arrangement with a forced heir. |
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Dispute over authenticity or content: The result may be years of litigation and a blocked inheritance. |
ARROWS, a Prague-based law firm, will represent your heirs in inheritance law disputes, challenges to the authenticity of a will, or the resolution of formal defects. |
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Conflict with the community property of spouses: Not realizing that you no longer consider part of the assets to be your own property; mistakes are very easy to make here. |
The specialists at ARROWS, a Prague-based law firm, will explain what share of the community property of spouses you can actually bequeath and how to express it correctly in the will. |
Other common mistakes: From duplicate wills to digital data
Multiple wills and their conflicts
If you have multiple wills drawn up at different times, it is important to correctly formulate their relationship to each other. A newer will generally revokes an older one, but only to the extent that they contradict each other (§ 1575(1) of the Czech Civil Code). For example, if the old will said “the house goes to the son” and the new one “the car goes to the daughter”, both bequests remain valid (provided they are not repeated and are not in conflict).
A mistake we often see: The testator draws up a new will but forgets to expressly state in it that they revoke all earlier dispositions. The result is ambiguity—lawyers and the court then have to decide which part of which will remains in force.
Best practice: Insert the following sentence into the new will: “I hereby revoke all my previous wills and other dispositions upon death.” (§ 1575(2) of the Czech Civil Code).
Digital assets and unknown accounts
A modern estate often includes digital assets: cryptocurrencies, online accounts, domains, photos in cloud storage, etc. If it is not known how to access these assets (missing passwords, access credentials), the heirs may lose them.
We recommend that every testator keep a list of all their digital accounts, passwords, and instructions on where this list is stored and how the heirs can access it. The will itself may bequeath digital assets, but without access information, their transfer may be difficult or impossible.
Cross-outs and amendments in a will
If you want to change a will, do not do it like in a school notebook. Vague rewriting, crossing out, and adding undermines confidence in the origin and authenticity of the will. In a dispute, the court will find it difficult to verify whether the amendment was made originally or later.
Correct procedure: Draw up a new will. It is safer and compliant with the law. Any change or addition to a will must meet the same formal requirements as the original disposition (§ 1577 of the Czech Civil Code).
A notarial will: The path to security and certainty
One of the easiest ways to avoid formal errors is to draw up a will in the form of a notarial deed (§ 1532(1)(c) of the Czech Civil Code). A notary, as a qualified legal professional and public official, will ensure all requirements are met—from proper identification to formal correctness.
A will drawn up in this way is then automatically registered in the central Register of the Notarial Chamber of the Czech Republic (ENS), ensuring that it can always be located after your death.
Advantages of a notarial will:
- All formal requirements are automatically met and the risk of invalidity due to formal defects is eliminated.
- The law considers it a public deed with increased evidentiary value.
- When authenticity or validity is challenged, the notarial deed has strong evidentiary value—the burden of proving invalidity lies with the person challenging the will.
- It is stored in a central register (ENS), so it will certainly be found after your death and cannot be lost or forged.
- The notary provides expert legal advice when formulating your intent and ensures clarity and unambiguity.
Disadvantage: The service requires payment of a notarial fee. For a simple notarial deed of a will, this is usually in the range of a few thousand Czech crowns (depending on complexity and the notarial tariff). Compared to the potential costs of disputes over invalidity or the interpretation of a vague will, it is a fully acceptable price for legal certainty.
Final summary
Drafting a will may seem like a simple matter—and in principle it is. But it is precisely this “simplicity” that leads people to draft it incorrectly or without sufficient attention to detail. The result is often invalid wills, court disputes between heirs, lengthy proceedings, and often even loss of assets.
The most common mistakes are surprisingly easy to fix if you know what to look for: a vaguely designated heir, an unclear description of assets, a missing witness, an incorrect number of witnesses, an omitted date, or unaddressed rights of forced heirs. All of these problems can be prevented with the right approach and a small amount of legal care.
If you do not want to risk your last will becoming invalid or the subject of lengthy court proceedings, you can entrust the matter to professionals.
The attorneys at ARROWS, a Prague-based law firm, specialize in inheritance law and will help you draft a will so that it is legally watertight, respects your wishes, and is understandable for the heirs. Whether you only want your will reviewed or you want to draft it from scratch in the form of a notarial deed (and we can accompany you to the notary if needed), our Czech legal team is at your disposal.
Contact us at consultation@arws.cz and speak with our Prague-based attorneys about the best way to proceed. A consultation will help you avoid unnecessary complications.
About the author
Disclaimer:
The information contained in this article is for general informational purposes only and serves as a basic guide to the issue as of 2026. Although we strive for maximum accuracy, laws and their interpretation evolve over time. We are ARROWS Law Firm, a member of the Czech Bar Association (our supervisory authority), and for the maximum security of our clients, we are insured for professional liability with a limit of CZK 400,000,000. To verify the current wording of the regulations and their application to your specific situation, it is necessary to contact ARROWS Law Firm directly (consultation@arws.cz). We are not liable for any damages arising from the independent use of the information in this article without prior individual legal consultation.
