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What Is the Biggest Mistake in a Will? A 2026 Guide
Table of Contents
- What Is the Biggest Mistake in a Will?
- The Legal Requirements for a Will UK: Getting the Basics Right
- Choosing an Executor for Your Will: The Decision People Rush
- What Happens If You Die Without a Will?
- Why People Put Off Making a Will (And What It Costs Them)
- How to Avoid the Biggest Mistake in a Will
- Frequently Asked Questions
Last Updated: October 4, 2026
What Is the Biggest Mistake in a Will?
The biggest mistake in a will is not signing it correctly. A will that is not signed and witnessed according to the legal rules is not worth the paper it is written on, no matter how carefully the words are chosen. This guide walks through the errors we see most often, what they cost families, and how to avoid them.
Most people assume the danger lies in complicated tax planning. In practice, the failures are far more basic. An unsigned will, a missing witness signature, a rushed choice of executor: these are the mistakes that send estates into dispute.
Below, we break down the biggest mistake in a will, the legal requirements that make a will valid, and the practical steps that keep your wishes intact.
The Legal Requirements for a Will UK: Getting the Basics Right
A will is only legally valid if it meets the requirements set out in section 9 of the Wills Act 1837, which remains the governing statute. Those rules are strict, and they exist to prevent fraud.
The core requirements are straightforward:
- The will must be in writing and signed by the person making it, known as the testator.
- The testator must intend to give effect to the will by that signature.
- Two witnesses must be present at the same time and attest the signature.
- Each witness must then sign the will in the presence of the testator.
A will that fails any of these steps is generally invalid. For a plain-English summary of how the Act applies, see the official guidance on the Wills Act 1837.
Signing and Witnessing: Where Wills Quietly Fail
Witnessing is where most DIY wills come unstuck. A common mistake is asking a beneficiary to act as a witness. If a witness or their spouse is left a gift in the will, that gift can fail, even though the rest of the will stands.
Another frequent error is witnessing a will over video or apart from each other. The witnesses must be together when they sign.
Choosing an Executor for Your Will: The Decision People Rush
Choosing an executor for your will is the decision most people make in a hurry, and it matters more than they realise. The executor is the person legally responsible for administering the estate: gathering assets, paying debts and tax, and distributing what remains.
Naming a single executor with no backup is a quiet trap. If that person dies, becomes ill, or simply does not want the role, the estate can stall for months.
A practical approach is to appoint two executors, or one executor plus a substitute. Think about who is organised, willing, and likely to outlive you. It does not have to be a family member.
What Happens When Your Executor Cannot Act
If no executor can act, the estate does not simply resolve itself. Someone has to apply to the court for permission to administer it, which adds time, cost, and stress at the worst possible moment.
The fix costs nothing: name a substitute executor in the will itself. This is one of the simplest protections you can put in place.
What Happens If You Die Without a Will?
Dying without a will means the law decides who inherits, not you. The rules of intestacy set out a fixed order of inheritance that may not match your wishes at all.
Under those rules, an unmarried partner has no automatic right to inherit, however long you have been together. Friends, stepchildren, and charities receive nothing unless the law happens to name them. If you have minor children, the courts may decide who cares for them.
For the full statutory order of distribution, see the official guidance on intestacy rules.
Why People Put Off Making a Will (And What It Costs Them)
Delay is the mistake behind almost every other mistake. Many people find the legal terminology confusing and keep putting it off, year after year. The cost of that delay is rarely financial at first; it is the uncertainty it leaves behind.
A common pattern is that someone drafts a will online, gets lost in the jargon, and never quite finishes it. An unsigned draft is legally worthless.
The real difference between a will that works and one that fails often comes down to a single conversation with someone who can explain it in plain English.
How to Avoid the Biggest Mistake in a Will
Avoiding the biggest mistake in a will comes down to getting the signing and witnessing right, and reviewing the document when your life changes. Here is a simple checklist to work through:
- Confirm the will is in writing and clearly dated
- Sign it in front of two witnesses who are both present
- Ensure neither witness, nor their spouse, is a beneficiary
- Have both witnesses sign in your presence
- Name at least one substitute executor
- Appoint a guardian if you have minor children
- Store the signed original somewhere safe and tell your executor where it is
- Review the will after marriage, divorce, a birth, or a major change in assets
If a will is not signed and witnessed correctly, it can be challenged or ignored entirely. That is why many people choose professional guidance over a template. At Staniland Estate Protection, we offer jargon-free advice and a comprehensive review so the document stands up when it matters. As one client put it, "The guidance was clear, the process was stress-free, and everything was explained in plain English."
| Mistake | Consequence | How to Avoid It |
|---|---|---|
| Not signed or witnessed | Will is invalid | Sign before two witnesses present together |
| Beneficiary as witness | Their gift fails | Choose independent witnesses |
| No substitute executor | Estate stalls | Name a backup executor |
| No will at all | Intestacy rules apply | Make a will and keep it updated |
Frequently Asked Questions
What makes a will invalid in the UK?
A will can be invalid if it was not signed in the presence of two witnesses, if the witnesses were also beneficiaries, if the testator lacked mental capacity, or if it was made under undue influence. A later will can also revoke an earlier one. These are some of the most common reasons a will fails, which is why legal requirements for a will UK must be followed precisely.
Can I write my own will without a solicitor?
Yes, you can write your own will, provided it meets the legal requirements for a will UK, including signing it in front of two witnesses who are not beneficiaries. However, DIY wills are more likely to contain errors or miss important provisions, especially for complex estates. A solicitor or estate planning professional can help ensure your wishes are legally protected.
What is the most common mistake when making a will?
The most common mistake is failing to update the will after major life changes such as marriage, divorce, or the birth of children. An outdated will can leave assets to the wrong people or become invalid. Regular reviews with a professional help ensure your will reflects your current wishes and circumstances.
Does a will need to be witnessed by two people?
Yes, in England and Wales a will must be signed by the testator in the presence of two witnesses, who must also sign in the testator's presence. Witnesses cannot be beneficiaries or the spouses or civil partners of beneficiaries. If this requirement is not met, the will may be invalid, meaning your estate could pass under intestacy rules.
The biggest mistake in a will is not the wording, it is the signing, witnessing, and review that people skip. Getting those basics right is what protects your family. Staniland Estate Protection offers tailored planning, expert guidance from Daniel Staniland LLB, and a clear, stress-free process designed to give you peace of mind. Book a free consultation with Staniland Estate Protection and secure your wishes for the people you love.