How to Update a Will in England & Wales: Codicil or New Will?

The rule you must never break: do not write on a signed will

The single most common mistake is crossing out a clause or writing a correction on a will that has already been signed. Under section 21 of the Wills Act 1837, alterations to a will made after it has been executed (signed and witnessed) are presumed to have been made after the signing date — meaning they are invalid. Worse, heavily altered documents can raise questions about the validity of the original will itself.

You have two legitimate options: a codicil or a new will. Both achieve the same outcome — changing what your will says — but they are suited to different situations.

Option 1: Adding a codicil

A codicil is a short, separate document that amends a specific part of an existing will. It must be signed and witnessed with exactly the same formalities as the original will (two independent adult witnesses, all present at the same time). The codicil is stored with the original will and read alongside it.

Codicils work well for:

• Adding or removing a single specific cash legacy (e.g. “I add a legacy of £5,000 to my nephew John Smith”)
• Changing an executor without touching the rest of the will
• Updating the address or description of a named beneficiary
• Revoking a specific gift without changing the residue

Codicils are not ideal for:

• Changes to the residue (who inherits the bulk of the estate)
• Changes that affect multiple clauses simultaneously
• Any situation where you already have one or more codicils
• Significant family changes (new marriage, divorce, new children)

Option 2: Writing a new will

In most cases, writing a new will is the safer, cleaner option. A new will typically starts with a standard clause revoking all previous wills (“I revoke all former wills and testamentary dispositions previously made by me”). This replaces the old will entirely, leaving no ambiguity.

Our Single Will Kit includes the revocation clause as standard. Once you have completed, signed, and witnessed the new will, shred the old one — keeping superseded documents creates confusion for your executor.

When you must write a new will (not a codicil)

After marriage or civil partnership

Marriage automatically revokes any existing will under section 18 of the Wills Act 1837, unless the will was made expressly in contemplation of that marriage. This is one of the most common reasons people unknowingly die intestate — they wrote a will years earlier, then got married and assumed it was still valid. Write a new will as soon as possible after getting married.

After divorce or dissolution

Divorce does not revoke your will, but it does cancel gifts to your former spouse and removes them as executor, treating them as if they had died on the date of the decree absolute. The rest of your will may not then reflect your intentions — particularly if you named your former spouse as the residuary beneficiary with no substitute. A new will is strongly advisable.

After having children or grandchildren

A will does not automatically include children born after it was made. You should review and, if necessary, rewrite your will after the birth of each child or grandchild you wish to benefit. If you have appointed a guardian for minor children under section 5 of the Children Act 1989, confirm they are still the right choice.

After the death of a beneficiary or executor

If a named beneficiary dies before you and there is no substitute gift provision, the gift “lapses” and falls into the residue (or causes intestacy for that part). If your executor dies, you need a new appointment. Either way, a new will is usually cleaner than a codicil.

What about crossing things out before signing?

Alterations made before the will is signed are valid, provided the will is signed and witnessed in its amended form. If you are using one of our DOCX templates, simply make your changes digitally before printing and signing. No marking up of a printed document is needed.

Keeping your will up to date

Most estate planning professionals suggest reviewing your will every 3–5 years and after any significant life event: marriage, divorce, new children, significant asset changes, moving abroad, or the death of a named beneficiary or executor. Our Essentials Bundle includes a 30-day action plan that covers review triggers and a simple personal inventory to make the process straightforward.

Frequently asked questions