A codicil is a legal document that amends an existing will without replacing it. Think of it as a formal postscript: the will stands, the codicil adjusts a clause or two, and at probate the two are read together as a single set of instructions. Codicils have existed for centuries, from the days when every will was drafted by hand and re-writing one from scratch cost real money. The tool survives because the need does: wills are long-lived documents and life keeps moving.
What a codicil can change
Legally, almost anything: a codicil can add gifts, remove them, change executors or guardians, and alter shares. In practice it is the right tool only for small, self-contained changes:
- Replacing an executor who has died or moved away
- Updating a beneficiary’s name after marriage, or an address
- Adding a cash legacy: a new grandchild, a charity, a friend
- Adjusting funeral preferences
- Correcting a small error the original will carried
The moment a change touches the structure of the will, who gets the residue, trusts, anything after a marriage or divorce, a new will is the better instrument. Layered amendments breed contradictions, and contradictions breed disputes.
The formalities are identical to a will’s
This is the point people miss. A codicil is a testamentary document, so section 9 of the Wills Act 1837 applies in full: it must be in writing, signed by you, with two witnesses present at the same time, each signing in your presence. The witnesses need not be the same people who witnessed the will, but the beneficiary trap applies here too: anyone who benefits under the codicil, or the will it amends, or their spouse or civil partner, must not witness it, or their gift is void. An unwitnessed "codicil", however clearly written, is legally a note.
A codicil must also identify its will
A good codicil names the will it amends by date, states which clause it changes and how, and confirms the rest of the will in full force. It is then stored with the will, unstapled and unclipped, so the two are found together. A codicil that surfaces without its will, or a will whose staple marks hint at a missing page, generates exactly the probate questions you were trying to avoid.
How many codicils is too many?
There is no legal limit, and the practical limit is low. One codicil is normal. Two is fine. By the third, executors are cross-referencing four documents to work out what you meant, and a fresh will costs little more than the codicil would. Some changes also read badly as amendments: cutting a family member’s share by codicil leaves a visible record of the change at probate, where a new will states the final position without narrating the history.
A codicil with Willful
Willful prepares codicils for £49, reviewed by an SRA-regulated solicitor before you sign, with the same witnessed-signing instructions as our wills. The review checks the thing DIY codicils get wrong most: that the amendment actually works alongside the will it is changing. And if your change turns out to be new-will territory, we say so and route you there instead, because selling you the wrong document helps nobody.