10 Common Mistakes When Making a Will

Section 9 of the Wills Act 1837 sets out exactly how a will must be signed for it to be valid, and the rules are stricter than most people expect. You must sign, or acknowledge your existing signature, in the presence of two witnesses who are both present at the same time, and each witness must then sign in your presence. Missing any part of this sequence, signing before the witnesses arrive, having them sign at different times, or having only one witness present, can make the whole will invalid.

This is the most common reason a will fails completely, and it is entirely avoidable with clear instructions. A guided process walks you through the exact order of signing, tells you what your witnesses need to do, and flags common errors such as remote witnessing arrangements that do not meet the legal requirements. See our full guide on how to sign a will for the step-by-step sequence to follow.

A witness must not be a beneficiary of the will, or the spouse or civil partner of a beneficiary, at the time of signing. If they are, section 15 of the Wills Act 1837 says the gift to that beneficiary fails, even though the will itself remains valid. This is a genuinely common mistake, particularly in family households where the most obvious people available to witness are also the people named in the will.

The safest approach is to use two independent adults with no interest in the estate at all, such as neighbours, colleagues, or professional witnesses, and to check this before anyone signs. A guided process asks directly whether your chosen witnesses stand to benefit, precisely to catch this before it causes a problem that cannot be undone without redoing the will.

Many wills carefully list specific gifts of money or possessions but never say what happens to everything else, known as the residuary estate. This can include the bulk of the estate's actual value, such as the family home, savings, and investments. If the residue is not dealt with, or the residuary gift fails for some reason, that part of the estate is distributed under the intestacy rules rather than according to your wishes.

This is one of the most consequential and most avoidable mistakes on this list, because it can undo the point of making a will in the first place. A structured will-writing process always asks who should receive the residue and does not let you finish without an answer. Our guide on what the residuary estate is explains this in more detail.

It is common to appoint a spouse, partner, or close friend as sole executor without naming anyone as a backup. If that person dies before you, is unable to act, or does not want to act when the time comes, and no replacement is named, the court has to appoint someone else, which takes time and can mean someone unfamiliar with your wishes ends up in charge of your estate.

Naming at least one replacement executor, and ideally appointing two executors from the outset, is simple to arrange and costs nothing extra. See our guide on choosing an executor for what makes someone a good choice and how many to appoint.

A will that simply says "I leave my estate to my son" does not automatically say what happens if that son dies before you do. Unless the will includes a substitute gift, that share can fail and fall into residue, or into intestacy if there is no residuary gift either, which may not be what you would have wanted, particularly if your son has children of his own who you would have expected to inherit in his place.

A well-structured will builds in substitute beneficiaries for major gifts, so there is a clear answer if the unexpected happens. Our guide on what happens if a beneficiary dies before you covers this in full, including how per stirpes gifts work for grandchildren.

If you have children under 18 and something happens to both parents, a will is the only way to formally nominate who should look after them. Without a guardianship appointment, this decision is left to the family court to work out, often at a time of real distress for the children involved, and not necessarily in line with what either parent would have chosen.

This is one of the most emotionally important parts of any parent's will, and it is easy to overlook if you are focused mainly on money and property. A good will-writing process asks about this directly rather than leaving it as an afterthought, and lets you name a first choice and a backup guardian.

Once a will is signed and witnessed, you cannot simply cross out a clause, write a note in the margin, or add a new gift by hand and expect it to take effect. Unattested alterations like this are generally treated as if they were never made, and in some cases can raise doubts about whether the will was tampered with, which can hold up probate while the alteration is investigated.

If your circumstances or wishes change, the correct routes are a formal codicil, signed and witnessed in the same way as a will, or making a new will altogether. For anything beyond a very minor change, a new will is usually simpler and less risky than a codicil, and a guided online process makes it straightforward to update your will whenever you need to.

A will does not automatically stay up to date with your life. Marriage or civil partnership revokes an existing will in almost all cases, meaning the estate can fall into intestacy if a new will is not made. Divorce does not revoke a will, but it does treat a former spouse as having died for the purposes of gifts and executor appointments, which can leave gaps. Having children, moving house, or a relationship ending are all good reasons to check whether your will still reflects your wishes.

A sensible habit is to review your will after any of these events, and as a matter of routine every few years even if nothing obvious has changed. Our guide on updating your will explains when a new will is needed and when a codicil might be enough.

Vague descriptions of gifts cause more disputes than almost anything else in will drafting. Leaving "my jewellery" to one person and "my personal effects" to another can lead to genuine disagreement about which items fall into which category, especially where sentimental value is involved. Similarly, naming a beneficiary only by a nickname or an ambiguous relationship, such as "my niece" when you have several nieces, can leave executors unsure who was actually meant.

Being specific costs nothing and prevents avoidable arguments between people who are already grieving. Use full names, clear descriptions of significant items, and specific relationships wherever possible, and consider a separate letter of wishes for smaller personal items that may change over time.

An online will works well for straightforward estates and family situations, and it is generally quicker, cheaper, and more consistent than a will written entirely from scratch by hand. But some circumstances genuinely call for professional advice, including complex trusts, business or agricultural assets, unmarried couples with property, international assets, or a family situation where a dispute is likely, such as a wish to leave someone out who might otherwise expect to inherit.

A guided online process should tell you plainly when your situation may need a solicitor rather than trying to handle everything itself. Getting this judgement right matters more than getting a will finished quickly. Our simple will online guide explains the kind of estate an online will suits best, and our step-by-step guide on making your will online sets out the whole process from start to finish.