Codicil or New Will? How to Change Your Will the Right Way

Once your will is signed and witnessed, it is not set in stone forever, but it is fixed in one important sense: you cannot simply cross something out, scribble in a new name, or staple on a fresh page and expect it to count. Life moves on, and your will needs to keep up. The question most people ask us is a practical one: should you make a small amendment with a codicil, or write a brand-new will from scratch? This guide walks you through how each method actually works in England and Wales, the strict signing rules they both have to follow, and the everyday DIY mistakes that quietly undo people's best intentions.

What a codicil actually is

A codicil is a short legal document that sits alongside your existing will and changes one or more parts of it, while leaving the rest in place. Think of it as a tidy, properly executed footnote rather than a rewrite. A codicil might appoint a replacement executor, swap one charity for another, or adjust a single cash gift. Crucially, it does not live inside your will — it is its own document, and it has to be read together with the original to make sense.

Codicil or new will: how to choose

There is no hard rule, but the deciding factor is usually how much you want to change and how clean the result needs to be. A codicil can be sensible for a single, self-contained tweak. Once you are making several changes, or touching who inherits the bulk of your estate, a fresh will is almost always the clearer route — partly because layering codicil upon codicil quickly becomes confusing for the people who have to interpret it after you are gone.

The signing rules are the same for both

Here is the part people most often get wrong. A codicil is not a casual add-on — it must be executed with exactly the same formality as the will it amends. Under the Wills Act 1837, the document must be in writing, signed by you (or by someone in your presence and at your direction), and your signature must be made or acknowledged in the presence of two witnesses, who then sign in your presence.

• In writing —the change is set out in a document, not just discussed or noted verbally.
• Signed by you —you sign it, or someone signs at your direction while you watch.
• Two witnesses —both must see you sign or acknowledge your signature, then sign themselves.
• Witnesses who do not benefit —a witness (or their spouse) who is also a beneficiary can lose their gift, so choose independent witnesses.

Because the formalities are identical, a codicil is not really the shortcut many people imagine. You still need the right witnesses in the same room at the same time. That is one reason we often find a clean new will is barely more effort — and leaves far less room for doubt.

Why DIY amendments go wrong

The most common — and most damaging — mistake is altering the original will by hand after it has been signed. Crossing out a name, writing a new figure in the margin, or adding a sticky note feels like a sensible update. In reality, unwitnessed changes made after signing are generally ignored, and in some cases they can throw doubt over the surrounding wording. The will may then be read as if your handwritten change never existed, leaving a gift to someone you no longer intended to benefit, or none to the person you did.

Other quiet pitfalls include codicils that contradict the will without saying which one wins, a codicil that refers to a will that has since been replaced, or storing the codicil somewhere your executors will never find it. Any of these can lead to delay, family disagreement, or part of your estate passing under the intestacy rules rather than your wishes.

Life events that should trigger a review

Some changes in your life affect your will automatically, whether you intended it or not. In England and Wales, getting married usually revokes an existing will entirely (unless it was specifically made in anticipation of that marriage), which can leave you unexpectedly without a valid will. Divorce does not revoke your will, but it generally treats your former spouse as having died before you for the purposes of gifts and executor appointments — which can leave gaps the will never anticipated.

• Marriage, civil partnership, divorce or dissolution
• The birth of children or grandchildren
• Buying a home, or a significant change in what your estate is worth
• An executor or beneficiary who has died, moved away, or fallen out of touch
• A change of heart about who should inherit or who should act for you

Our separate guide on when and why to update your will explores these triggers in more depth. The point here is simpler: when one of these moments arrives, the right response is rarely a pen and the original document — it is a proper review and, where needed, a fresh, correctly witnessed will or codicil.

Here to help, close to home

Changing your will the right way is not complicated once you know the rules — but it is easy to get wrong on your own, and the people who pay for that are usually your family. Aaron Johnson is a solicitor and STEP-qualified Trust and Estate Practitioner, and Safe Harbour Legal helps people across Bridlington, Driffield, Filey, Hornsea, Beverley, Bempton, Flamborough and the wider East Riding get their wills right — whether that is a single tidy codicil or a clean new document. Whether you are in Bridlington Old Town or out across the Wolds, the first call is free, the fees are fixed rather than a slice of your estate, and a home visit can be arranged if that is easier. There is no pressure and no obligation — just a clear, friendly answer to a question worth getting right.