What Is a Codicil UK (2026)? How to Amend a Will Without Making a New One

A codicil is a separate legal document that supplements, modifies, or partially revokes an existing will without replacing it entirely. Key characteristics: (1) WHAT IT CAN DO: add new gifts or legacies not in the original will; change an existing gift (e.g. increase or decrease an amount; change the recipient); remove a gift or clause from the will; appoint a new executor or change an existing executor; appoint a guardian; add or change a trustee; revoke (cancel) a specific clause while leaving the rest of the will intact; (2) WHAT IT CANNOT DO: a codicil cannot correct an ambiguity or mistake in the original will without a court application. It operates as an addition or variation — not as a correction. To fix a clear drafting error, a deed of rectification (via the court) or a new will may be necessary; (3) IT IS LEGALLY SEPARATE: a codicil is a distinct document that must be kept with the original will. On death, the probate application is made for the will AND all codicils together — the executor submits both documents to the Probate Registry. The Grant of Probate will name both the will and the codicils as the admitted documents; (4) MULTIPLE CODICILS: there is no legal limit on the number of codicils a testator can make. However, more than 2-3 codicils creates practical risks — confusion about which version of the will is operative, conflicts between documents, and difficulty for the executor in reconciling the full intentions of the testator; (5) HISTORICAL USE: codicils were common before digital will-writing services existed — making a new will required visiting a solicitor and paying again. Today, with DIY will kits available for £35, making a new will is almost always preferable to a codicil for anything other than a very minor change.

A codicil must comply with the same execution requirements as a will under Wills Act 1837 s.9: (1) EXECUTION REQUIREMENTS: (a) IN WRITING: the codicil must be a written document (handwritten or typed). Oral (spoken) codicils have no legal effect; (b) SIGNED BY THE TESTATOR: the testator must sign the codicil. The signature should be at the foot of the document, but anywhere on the document is valid under WA 1837 s.9 as amended. A testator who cannot sign may make a mark, or direct another person to sign in their presence; (c) TWO WITNESSES: the signature must be made (or acknowledged as already made) in the presence of two witnesses present at the same time. The witnesses must then each sign the codicil in the testator's presence; (d) WITNESSES CANNOT BENEFIT: WA 1837 s.15 — any gift in the codicil to a witness (or their spouse/civil partner) is void (the codicil itself remains valid but the gift is lost). Witnesses must be independent of any benefits under the codicil; (2) SAME WITNESSES AS THE ORIGINAL WILL? Not required — the codicil witnesses do not need to be the same people who witnessed the original will. Two new witnesses are perfectly acceptable; (3) DATING: not strictly required for validity, but the codicil should be dated to establish the order of documents and to assist in construction if there are conflicts with the original will. If there are multiple codicils, dating is essential; (4) PROFESSIONAL WORDING: a properly drafted codicil should clearly identify: the original will by date; the specific clause being added, varied, or revoked; any new appointments or changes; a confirmation that the rest of the original will remains in full force and effect ('In all other respects I confirm my said Will dated [date]'); (5) ATTESTATION CLAUSE: the same attestation clause used in a will ('Signed by the above-named [testator] as their Codicil in our presence and then by us in theirs') is appropriate. An attestation clause creates a presumption of due execution.

A codicil is generally appropriate only for minor, isolated changes. Modern practice strongly favours making a new will in most circumstances: (1) SITUATIONS WHERE A CODICIL MAY BE APPROPRIATE: (a) Small monetary legacy: adding a £500 cash gift to a new grandchild, where the rest of the will remains unchanged; (b) Substituting a single executor: one executor has died and needs to be replaced, with no other changes needed; (c) Adding a single specific bequest: adding a bequest of a named item (e.g. 'I give my grandfather's watch to my nephew') that was not in the original will; (d) Revoking a single gift: removing a legacy to a specific person who has since died or with whom the testator has fallen out; (2) SITUATIONS WHERE A NEW WILL IS CLEARLY BETTER: (a) Change in relationship (marriage, divorce, new partner): marriage automatically revokes any existing will (WA 1837 s.18) — a new will is essential. Divorce voids gifts to an ex-spouse but not the rest of the will (WA 1837 s.18A) — a new will is strongly advisable; (b) Change in assets (new property, significant investment): where the nature or distribution of assets changes significantly, a comprehensive review of the will is more appropriate than piecemeal amendments; (c) New or updated guardianship wishes: changing the guardian of minor children is important enough to warrant a clean document; (d) Tax planning changes: where the IHT strategy needs to be updated (e.g. after a spouse dies, or after the pension IHT April 2027 change), rewriting the will with proper advice is better; (e) Where the original will is old or unclear: if the original will was made many years ago and may have ambiguities, it is better to make a fresh will rather than patch it; (3) RISK OF CONTRADICTIONS: a codicil that contradicts a clause in the original will raises construction questions — which governs? Courts generally apply the codicil as the later expression of intent, but ambiguities can trigger disputes and litigation. A new will eliminates this risk entirely.

A codicil has the same storage and registration requirements as a will: (1) NO OFFICIAL REGISTRATION REQUIRED: like a will, a codicil does not need to be registered with any government body to be valid. However, both the will and all codicils must be available on death for the probate application; (2) STORE WITH THE ORIGINAL WILL: the codicil must be kept together with the will — or at minimum, both documents must be identifiable and findable when needed. The executor submits both the will and all codicils to the Probate Registry when applying for a Grant; (3) NATIONAL WILL REGISTER: the National Will Register (administered by Certainty) is an optional private register for wills and codicils. Registering both the will and subsequent codicils helps ensure they are located after death. There is a small registration fee; (4) SOLICITOR'S CUSTODY: if a solicitor holds the original will, the codicil should also be stored with the solicitor (or at minimum, the solicitor should be notified that a codicil has been made and told where it is kept); (5) WHAT HAPPENS IF THE CODICIL IS LOST: if the codicil cannot be found, there is a presumption (rebuttable) that it was revoked by the testator. If the codicil was in the testator's custody and cannot be found on death, the court presumes it was intentionally destroyed. The original will may then be admitted to probate without the codicil — which may not reflect the testator's final intentions; (6) SAFE STORAGE: store both the will and codicil(s) together in a fireproof location (home safe; solicitor's deed storage; bank safe deposit box). Tell the executor where they are stored. Consider using the National Will Register to record their existence and location.

A codicil can revoke an entire will — but this is an unusual and inadvisable approach: (1) FULL REVOCATION BY CODICIL: yes, technically a codicil can include a revocation clause cancelling the entire previous will. However, if the intention is to revoke the whole will, the standard approach is simply to make a new will (which can include a revocation clause at the start: 'I revoke all former wills and testamentary dispositions'). Revoking a will via a codicil without replacing it would leave the testator with no will at all — resulting in intestacy; (2) PARTIAL REVOCATION: the more common use of revocation in a codicil is to revoke a specific clause or legacy — 'I hereby revoke clause 4 of my Will dated [date] and substitute the following...'. This is a legitimate use of a codicil; (3) HOW WILLS ARE REVOKED: under WA 1837 s.20, a will (or part of it) can be revoked by: (a) a later will or codicil that expressly revokes it; (b) a later will or codicil that is inconsistent with it (implied revocation); (c) marriage (WA 1837 s.18 — automatic revocation); (d) physical destruction of the will with the intention to revoke (burning, tearing, etc.) — but this requires simultaneous act + intention; (e) an unwitnessed alteration does NOT revoke a will — alterations must be separately executed; (4) DIVORCE DOES NOT REVOKE: divorce under WA 1837 s.18A voids gifts to an ex-spouse and removes them as executor — but does not revoke the will entirely. The rest of the will stands. This is why a new will after divorce is strongly recommended; (5) PRACTICAL GUIDANCE: use a codicil only for minor, isolated changes. For anything substantive — especially changes involving IHT, family structure, major assets, or multiple clauses — make a new will. The cost of a WillSafe UK will kit (from £35) is minimal compared to the risk of a codicil creating ambiguity or unintended consequences.