Codicil to a Will UK (2026): What It Is, How to Write One & When to Write a New Will Instead
Quick answer
A codicil is a formal legal amendment to your will — signed and witnessed exactly like a will (two independent adults, Wills Act 1837). It is best for small, targeted changes: a new executor, an added gift, a corrected name. For anything significant — rewiring who inherits, more than two changes, or after marriage or divorce — write a new will instead. Multiple codicils create confusion at probate.
What is a codicil?
A codicil is a supplementary legal document that modifies, adds to, or partly revokes an existing will. It is governed by the same rules as a will under the Wills Act 1837 — the witnessing requirements are identical. At probate, the original will and all codicils are read together as a single testamentary statement.
Codicils were historically common when wills were handwritten and expensive to redraft. Today, with typed and printed wills becoming standard, writing a new will is usually faster and no more expensive — which is why most solicitors and will-writing services recommend a new will for all but the most minor changes.
Legal requirements for a valid codicil
A codicil is only valid in England and Wales if it meets the same requirements as a will under section 9 of the Wills Act 1837:
In writing
Typed or handwritten. No audio or video codicils.
Signed by the testator
Or by someone else in the testator's presence and at their direction (e.g. if they cannot physically sign).
Two independent witnesses
Both present at the same time when the testator signs. Neither can be a beneficiary of the will or codicil — or their spouse or civil partner.
Witnesses sign in the testator's presence
All three parties must be present. A witness cannot sign later or in a different room.
A codicil that fails any of these requirements is invalid. The original will still stands — but the amendment has no effect. The most common errors: a beneficiary witnesses; only one witness signs; or the codicil is signed after the witnesses have left.
What a codicil can and cannot do
| A codicil CAN | A codicil CANNOT (use a new will) |
|---|---|
| ✓ Change the name of an executor | ✗ Completely revise who inherits the residue |
| ✓ Add or remove a specific gift (e.g. £1,000 to a new grandchild) | ✗ Undo a marriage or divorce revocation |
| ✓ Correct a minor error (wrong name spelling, outdated address) | ✗ Replace trust provisions or add complex new ones |
| ✓ Change funeral wishes if not already in a separate planner | ✗ Untangle conflicts between multiple existing codicils |
| ✓ Add a substitute executor if the primary executor has died | ✗ Operate as a standalone instruction — it must reference the original will |
The multiple-codicil problem
There is no legal limit on the number of codicils you can add to a will. In practice, however, accumulating codicils creates significant risk:
- Ambiguity — if a later codicil amends the same clause as an earlier one, which version governs? Courts have to determine the testator's intent from conflicting documents.
- Lost codicils — each codicil is a separate document. If one is lost, misfiled, or destroyed (even accidentally), the will may not reflect the final wishes.
- Probate delay — the more documents, the more the probate registry scrutinises the package. Executors must submit all codicils with the original will.
Solicitors regularly advise clients with more than one codicil to consolidate into a new will. A fresh will with a standard revocation clause wipes the slate clean.
How to write a codicil: a practical structure
A codicil should include:
- A title: "Codicil to the Will of [Full Name]"
- Your full name, address, and the date
- A reference to the original will: "This is a codicil to my Will dated [date]"
- A clear statement of the amendment: "I revoke the gift of £500 to John Smith and instead give £500 to Jane Smith of [address]"
- A confirmation clause: "In all other respects I confirm my said Will"
- Signature and attestation (two witnesses, all present, dated)
Codicil vs new will: when to choose which
| Change needed | Codicil? | New will? |
|---|---|---|
| Add a specific cash gift to a new grandchild | Yes | Not required |
| Change one executor to another | Yes | Not required |
| Correct a spelling error in a beneficiary's name | Yes | Not required |
| Change main beneficiary / residue distribution | No | Write a new will |
| Marriage or civil partnership | No — marriage revokes the will | Write a new will |
| Divorce or separation | No | Write a new will to be safe |
| Already have 2+ codicils | No | Consolidate — write a new will |
| Add or remove trust provisions | No | Write a new will with specialist advice |
Writing a new will with WillSafe UK is straightforward and costs £39.99 for a single will — for most situations, a clean new will is a better investment than a codicil and the risk of conflicting documents.
Frequently asked questions
What is a codicil to a will in England and Wales?▼
A codicil is a formal legal document that amends or supplements an existing will. It must be signed by the testator and witnessed by two independent adults in the same way as the original will. A codicil is stored with the will and interpreted alongside it — forming part of the complete testamentary instruction.
Does a codicil need to be witnessed in the UK?▼
Yes. A codicil has exactly the same legal requirements as a will under section 9 of the Wills Act 1837: it must be in writing, signed by the testator (or by someone else at the testator's direction), and witnessed by two independent adults who are both present at the same time. A beneficiary — or their spouse or civil partner — cannot be a witness without losing their gift.
Does making a codicil revoke the original will?▼
No. A codicil does not revoke the original will — it amends specific parts of it. The will and all its codicils are read together at probate. Only a specific revocation clause in a codicil, or writing a new will that expressly revokes all prior wills and codicils, cancels the original will.
When should I use a codicil rather than writing a new will?▼
A codicil is suitable for small, targeted changes: adding or removing a beneficiary for a specific gift, changing an executor, adding a new specific bequest, or correcting a minor error. For major changes — rewiring who inherits the residue, significant changes to trust provisions, marriage or divorce, or when there are already multiple codicils — write a new will. A new will is always cleaner and reduces the risk of ambiguity.
How many codicils can I add to a will?▼
There is no legal limit. However, multiple codicils create confusion — particularly if the same clause is amended more than once, or if an earlier codicil is partly contradicted by a later one. Solicitors regularly encounter estates with four or five codicils that require careful interpretation. After more than one or two amendments, writing a new will is strongly recommended.
Can I attach a codicil directly to the original will?▼
No — and this is a common mistake. A codicil must be kept with the will but not physically attached (stapled, glued, or clipped) to it. Marks on or damage to a will caused by physical attachment can raise questions about whether the will was tampered with and may complicate probate. Keep them in the same envelope or folder, separately.
Does marriage or divorce affect an existing codicil?▼
Yes. In England and Wales, marriage automatically revokes both the will and any codicils to it (Wills Act 1837, s.18). Divorce does not automatically revoke the will or codicils, but any gifts to a former spouse or their appointment as executor lapse automatically (Wills Act 1837, s.18A). If you marry or divorce, write a new will — do not try to patch it with a codicil.
Update your will cleanly — write a new one
For most changes, a fresh WillSafe UK will kit is simpler, safer, and no more expensive than a codicil — and it eliminates the multiple-document confusion risk entirely.
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This article is for general information only and does not constitute legal advice. WillSafe UK is not a firm of solicitors. Last reviewed 13 May 2026.