A will is one of the most important documents you will ever sign. It takes little time to prepare, costs relatively little, and yet it carries your wishes at the one time you can no longer express them yourself.
That contrast, minimal effort, significant consequence, has helped fuel the growth of the online will-writing industry. Templates, subscription services, DIY kits and "three questions and you're done" apps all promise the same thing: a legally valid will, prepared in less time than it takes to renew your car insurance.
The uncomfortable truth is that they are often right. A DIY will can be legally valid. But "legally valid" is not the same as "achieves what you intended". A will can meet the legal requirements for validity while still creating uncertainty, failing to account for important circumstances, or producing outcomes you never anticipated.
The pitfalls below are among the most common we encounter and almost all of them come to light only after it is too late to put things right.
Most people don't build an estate at the end. They build it slowly, over decades.
A deposit for one child's first flat. School fees for one set of grandchildren but not another. A larger gift to the child who went through a divorce, or the one who paused their career to care for a parent. A loan to a sibling's business that was never quite called in.
These gifts are often acts of love, made around kitchen tables or during difficult moments in hospital corridors rather than in solicitors' offices. Precisely because they happen informally, they are rarely reflected in a DIY will.
When the will is eventually read, the estate may appear to be divided equally. In reality, the overall distribution can be very different once substantial lifetime gifts are taken into account. If your intention is for each beneficiary to receive broadly the same overall benefit, a professionally drafted will can include an equalisationclause. This allows significant lifetime gifts to be brought back into the calculation, helping ensure that earlier generosity is taken into account when the estate is divided.
A standard DIY will cannot do this because it never asks the question. It simply divides the estate that remains at the date of death, leaving families to resolve any perceived unfairness themselves, often after relationships have already begun to fray.
A UK will is not automatically effective everywhere. Many DIY templates assume English or Scottish law applies throughout, a safe assumption for a house in Surrey, but not necessarily for a villa in Spain, a chalet in France or property elsewhere overseas.
Some countries, particularly in Europe, have forced heirship rules that reserve part of an estate for close relatives regardless of what your will says. In some cases, a carefully drafted will can elect for the law of your nationality to apply instead. A DIY template rarely asks where your assets are, whether you need a separate foreign will, or whether your wills could conflict.
Most DIY wills assume a single death. Estate planning rarely works that way.
If everything passes outright to a surviving spouse, they become free to leave those assets however they choose. Family heirlooms or sentimental possessions you intended for your own children may ultimately pass elsewhere.
A professionally drafted will can protect those intentions through specific gifts or trusts, ensuring assets end up where you intended, even after a second death.
DIY wills are at their weakest in blended families. Second marriages, stepchildren and children from previous relationships all create competing expectations that informal understandings cannot reliably resolve.
Conversations are helpful, but they are not legally binding. A carefully drafted will, supported where appropriate by trusts and letters of wishes, provides certainty when memories, relationships and circumstances inevitably change.
One of the greatest risks arises when a will is prepared late in life, following the onset of dementia, a stroke or another serious illness.
A valid will requires more than a signature. Under the Mental Capacity Act 2005, the testator must understand the nature and effect of the will, the extent of their estate, the claims of those who might reasonably expect to benefit, and must not be affected by any disorder of the mind that impairs their judgment.
Where capacity may be in doubt, a solicitor will ordinarily follow the "golden rule" by obtaining a contemporaneous medical assessment, keeping detailed attendance notes and ensuring the client understands the document before it is executed.
A DIY will offers none of these safeguards. It cannot assess capacity, identify undue influence or create an evidential record of the circumstances in which the will was made. If the will is later challenged, the absence of that evidence can make defending its validity significantly more difficult.
A will is one of the few documents where a single word can alter who inherits an estate.
Although there are legal provisions that allow the courts to rectify certain drafting errors, that process requires litigation, evidence and expense. More importantly, rectification is limited: the courts can correct clerical mistakes, but they cannot rewrite a will to reflect an intention that was never properly expressed.
The most common errors in DIY wills are often technical rather than obvious. A gift may fail because it is poorly defined, a residuary clause may not reflect changing family circumstances, a property gift may lapse if the property has been sold. Marriage can also revoke an existing will unless it was drafted in contemplation of that marriage.
In each case, the person best placed to explain their intentions is no longer able to do so.
Equally important is what happens if the drafting is negligent. Where a solicitor prepares a defective will, disappointed beneficiaries may have a claim in negligence.
The position is very different for many unregulated will-writing services. Will-writing is not a reserved legal activity under the Legal Services Act 2007, meaning providers may operate without formal legal qualifications, regulatory oversight or professional indemnity insurance. If problems emerge years later, there may be little practical recourse.
A low-cost will can represent a genuine saving at the point of purchase. The question is whether that saving justifies the risk of uncertainty, litigation and unintended outcomes for those left behind.
Before choosing a DIY will, it is worth considering whether your circumstances involve lifetime gifts, overseas assets, blended families, vulnerable beneficiaries, questions of capacity or complex succession planning. If they do, professional advice is often less about producing a valid will than ensuring your wishes can be carried into effect when they matter most.
Estate planning isn't really about the piece of paper. It is about the people who will still be in the room after you.
Sometimes a straightforward will genuinely is enough. A single life, a single jurisdiction, a single family, uncomplicated assets, robust capacity, a properly qualified drafter, a well-drafted simple will can absolutely do the job. That is fine.
Just make sure the simplicity of the document reflects the simplicity of your life, and not the limits of the template. A will is a letter to the future written in a language you won't be around to translate. It is worth making sure it says what you actually meant.
