Common Estate Planning Mistakes to Avoid

The most common estate planning mistakes are having no will, letting an old one drift out of date, gifting without records, assuming everything simply passes to a spouse, and treating tax as the only question. Each is avoidable, and most people fix them by writing things down clearly and reviewing them after big life events.

None of these mistakes is exotic. They tend to surface only after a death, when the family is dealing with the consequences rather than the choices. This guide walks through the ones that come up most often in England and Wales, what tends to go wrong, and the way many people approach them. It sits within our wider estate planning guide. Figures are current as at July 2026 and are subject to change.

What are the most common estate planning mistakes?

The recurring ones are: dying without a valid will, relying on a home-made will that fails on a technicality, forgetting to update a will after marriage or divorce, making gifts without keeping records, and assuming a spouse automatically inherits everything. Poor record-keeping and ignoring later-life care costs round out the list. Most are errors of omission rather than bad intentions.

General points drawn from gov.uk/inheritance-tax and gov.uk/make-will, as at July 2026 and subject to change.

Having no will, or a DIY will that fails

Dying without a valid will means the intestacy rules decide who inherits, and those rules follow a fixed order that may not reflect your wishes (gov.uk, intestacy rules, as at July 2026, subject to change). A home-made will can go wrong too, often through faulty witnessing or wording that is open to more than one reading, which can make it invalid or slow to administer.

In England and Wales a will generally needs to be in writing, signed, and witnessed by two people who are present at the same time, and a witness or their spouse should not be a beneficiary, or that gift can fail (gov.uk/make-will, as at July 2026, subject to change). Because small errors can have large effects, many people choose to have a will drafted or checked by a qualified professional. Our note on How to Write a Will sets out the formalities.

Letting a will fall out of date

A will can quietly stop matching your life. In England and Wales marriage generally revokes an earlier will unless it was made in contemplation of that marriage, and divorce treats a former spouse as having died for the purposes of the will, so gifts to them usually fail (gov.uk, wills and marriage or divorce, as at July 2026, subject to change). A new child, a death among your beneficiaries, or a house move can all leave an old will out of step.

There is no fixed renewal date, but many people review a will after any major life event and otherwise every few years. Small changes are usually made by a codicil or a new will rather than by writing on the original, since marking the signed document can cause problems. It can be worth discussing with a qualified professional what a change means for the rest of the plan. See also what not to put in a will.

Assuming a partner or spouse inherits everything

Two beliefs cause trouble here. The first is that an unmarried partner inherits automatically: under the intestacy rules a cohabiting partner has no automatic right to inherit, however long the relationship (gov.uk, intestacy rules, as at July 2026, subject to change). The second is that leaving everything to a spouse is the whole answer on its own, when the tax often simply moves to the second death.

Transfers between spouses and civil partners are generally exempt, and any unused nil-rate band and residence nil-rate band can pass to the survivor, so up to £1,000,000 may be available on the second estate depending on circumstances (gov.uk, as at July 2026, subject to change). That can be sensible, but a plan that stops at the first death may leave questions unanswered for children or a blended family.

Trying to give assets away to avoid care fees

This is where good intentions can misfire. Where a local authority decides a person deliberately deprived themselves of assets to reduce a care charge, it can treat them as still owning that asset, known as notional capital, so the transfer does not achieve what was hoped (gov.uk, care and support statutory guidance, as at July 2026, subject to change). There is no fixed cut-off date for how far back this can be considered.

The lawful focus is care fees planning, meaning understanding the means test, the disregards and the funding routes, rather than deliberately giving assets away. Deliberately transferring a home or savings to sidestep future care costs can be challenged and is a mistake many families make without realising. It can be worth discussing with a qualified professional, and Age UK publishes a helpful overview of the deprivation of assets rules.

How the mistakes differ in Scotland and Northern Ireland

Inheritance tax is UK-wide, so the £325,000 nil-rate band and the 40% rate apply across all four nations (gov.uk, as at July 2026, subject to change). Succession law differs, though. Scotland has legal rights that can give a spouse and children a fixed share regardless of the will, and it uses confirmation rather than probate, so a will that ignores those rights can create a mistake unique to Scotland. Northern Ireland has its own probate and intestacy rules. Where an estate touches more than one nation, it can be worth taking advice in each.

Frequently asked questions