Codicil to a Will UK (2026): What Is a Codicil, When to Use One, and How to Execute It

A codicil is a formal legal document that AMENDS, adds to, or cancels provisions in an existing will without replacing the entire will: (1) THE BASIC CONCEPT: instead of making a completely new will every time a small change is needed, a testator can make a codicil that says, in effect, 'I amend my will dated [date] as follows: [specific changes]'. The original will and the codicil are read TOGETHER as if they were a single document; (2) WHAT A CODICIL CAN DO: a codicil can: (a) ADD a new legacy or gift not included in the original will; (b) CHANGE or REMOVE an existing legacy (e.g. increase from £5,000 to £10,000, or revoke a specific bequest entirely); (c) CHANGE EXECUTORS — appoint a new executor or remove one; (d) CHANGE TRUSTEES or update trustee provisions; (e) ADD OR REMOVE BENEFICIARIES from an existing class; (f) CONFIRM OR REPUBLISH the original will (bringing it up to date as of the codicil date — useful if there were prior alterations); (3) WHAT A CODICIL CANNOT EASILY DO: a codicil should NOT be used to: (a) make comprehensive changes across multiple provisions — this creates a confused patchwork of documents; (b) deal with complex structural changes (e.g. converting from a simple gift to an elaborate trust); (c) clearly revoke the entire original will and start again — use a new will instead; (4) INTERACTION WITH THE ORIGINAL WILL: where a codicil is inconsistent with the original will, the CODICIL PREVAILS — it is the later document. The original will provision is treated as revoked to the extent of the inconsistency. All provisions of the original will that are not altered by the codicil remain fully effective; (5) MULTIPLE CODICILS: it is possible to make more than one codicil to the same will — a second codicil amending the first codicil and the original will, and so on. However, multiple codicils quickly become very difficult to read and administer together. A new will is generally preferable once more than one or two changes are needed.

A codicil must comply with EXACTLY THE SAME formal requirements as the original will under the Wills Act 1837 s.9: (1) THE SAME FOUR REQUIREMENTS: (a) IN WRITING: the codicil must be in writing — typed or handwritten; (b) SIGNED BY THE TESTATOR: the testator must sign (or acknowledge their existing signature) at the end of the codicil; (c) TWO WITNESSES PRESENT SIMULTANEOUSLY: two independent adult witnesses must be present at the same time when the testator signs or acknowledges the codicil. They must be physically present simultaneously — not signed separately; (d) EACH WITNESS ATTESTS AND SIGNS: each witness must attest (acknowledge that they have seen the testator sign or acknowledge) and sign the codicil in the testator's presence; (2) DO THE WITNESSES NEED TO BE THE SAME PEOPLE AS FOR THE ORIGINAL WILL? NO — the witnesses to a codicil do NOT need to be the same people as the witnesses to the original will. Two completely different people can witness the codicil. There is no requirement for any connection between the codicil's witnesses and the will's witnesses. The requirements are simply that the codicil's two witnesses are adults, are present simultaneously, and are not beneficiaries (or spouses/civil partners of beneficiaries) under either the will or the codicil; (3) BENEFICIARY WITNESS RULE (s.15): the beneficiary witness rule (Wills Act 1837 s.15) applies to codicils just as it does to the original will. If a person who is a beneficiary under the codicil (or the spouse/civil partner of a beneficiary) witnesses the codicil, their gift under the codicil is void; (4) REPUBLICATION EFFECT: where a codicil CONFIRMS OR REPUBLISHES the original will, the will is treated as if it had been made on the date of the codicil. This can have important effects: (a) it may validate previously void alterations in the original will (if they were made after the will was executed and before the codicil — they are 'caught' by the codicil date); (b) it may affect the application of the Wills Act 1837 s.18 (revocation by subsequent marriage) — if the will was revoked by marriage but a codicil was made after marriage that republishes it, the will may be revived.

The choice between a codicil and a new will depends on the nature and extent of the changes needed: (1) WHEN A CODICIL IS APPROPRIATE: a codicil is suitable for: (a) SIMPLE, ISOLATED CHANGES: changing one or two specific legacies, adding a new specific gift, or updating an executor appointment — especially where the rest of the will is complex and does not need changing; (b) MINIMAL COST AND EFFORT: a codicil can be shorter and quicker to execute than a full new will, particularly for a straightforward amendment; (c) PRESERVING A PROFESSIONALLY DRAFTED WILL: if the original will was carefully drafted by a solicitor with complex trust provisions, a codicil may be preferable to retyping the entire will (with the attendant risk of errors); (2) WHEN A NEW WILL IS PREFERABLE: a new will is preferable when: (a) MAJOR STRUCTURAL CHANGES: the underlying structure of the will changes significantly (e.g. adding a property trust, changing residue beneficiaries, or revoking most of the specific gifts); (b) CHANGED CIRCUMSTANCES: marriage, divorce, birth of children, significant change in wealth — all typically warrant a comprehensive new will; (c) MULTIPLE AMENDMENTS ALREADY MADE: if a codicil already exists, a further set of changes should generally lead to a new will rather than a second codicil; (d) CONFIDENTIALITY: a codicil is submitted to the Probate Registry alongside the original will and becomes PUBLIC on grant of probate — just as the will itself does. If the testator does not want people to know that only a small amendment was made (or the nature of the amendment), a new will ensures all provisions are set out in one document; (e) CLARITY AND EASE OF ADMINISTRATION: personal representatives find a single current will much easier to administer than a will plus one or more codicils, particularly where the codicil uses language like 'I revoke clause 4 of my will dated...' which requires cross-referencing; (3) TAX PLANNING NOTE: if the changes relate to IHT planning (e.g. adding a charitable legacy, adjusting residue beneficiaries), the interaction of the codicil with the original will should be considered holistically — sometimes the codicil changes the IHT position of the estate in ways not anticipated if the full will is not reviewed at the same time.

Yes — a codicil is submitted to the Probate Registry alongside the original will when applying for a grant of probate: (1) BOTH DOCUMENTS REQUIRED: the personal representatives (executors) must submit BOTH the original will AND the codicil (and any further codicils) to the Probate Registry as part of the probate application. The Probate Registry will check that the codicil properly executes to the same s.9 standard as the will; (2) GRANT ISSUED IN RESPECT OF BOTH: the grant of probate (or letters of administration with will annexed) will refer to the will dated [date] AND the codicil dated [date]. The grant authorises the executors to administer the estate in accordance with both documents read together; (3) BOTH BECOME PUBLIC: when a grant of probate is issued, the will and all codicils become PUBLIC DOCUMENTS — available for anyone to search at the Probate Registry (gov.uk/search-will-probate). This means both the original will and the codicil are disclosed together publicly; (4) WHAT IF THE CODICIL IS LOST? If the codicil was executed but cannot be found at the date of death, it is PRESUMED TO HAVE BEEN DESTROYED with the intention of revoking it — just as a lost original will is presumed revoked by destruction. The presumption is rebuttable but requires strong evidence of the last known contents of the codicil. Keep codicils with the original will; (5) CODICIL REVOKES WILL CLAUSE BY CLAUSE: on a grant of probate, the Probate Registry checks that the codicil does not purport to revoke the entire will. A codicil that says 'I hereby revoke my will dated...' in full is actually a NEW will (even though headed 'codicil') — provided it meets the s.9 formalities. The Probate Registry will treat the documents according to their legal effect, not merely their heading.

A codicil can REPUBLISH (revive) a will that had been altered or in some cases a will that was partly revoked — but it CANNOT revive a will that was completely revoked by a later will, unless specific steps are taken: (1) REPUBLICATION BY CODICIL: when a testator makes a codicil that REFERS TO and CONFIRMS the original will, the will is treated as REPUBLISHED at the date of the codicil. The will 'speaks' from the codicil date, not from the original will date. Effect: (a) alterations made after the original will execution but before the codicil are treated as incorporated into the re-executed will and may become valid; (b) a will that was partially revoked (e.g. by alteration) may be wholly republished; (2) CANNOT REVIVE A FULLY REVOKED WILL: where the original will was completely revoked by a LATER WILL containing an express revocation clause, a codicil to the original will CANNOT revive it — the original will simply does not exist anymore as a document. There is nothing for the codicil to amend or republish (Re Haynes (1887)); (3) CODICIL MADE AFTER MARRIAGE (REVOCATION BY MARRIAGE): where a will was revoked by the testator's subsequent marriage (Wills Act 1837 s.18), a codicil made AFTER the marriage to the revoked will CANNOT republish it — because the original will was already wholly revoked. The testator must make an entirely new will; (4) PRACTICAL USE OF REPUBLICATION: republication is particularly useful where: (a) a will has unwitnessed alterations — a codicil that describes the will as 'my will dated [date] as altered' and is properly executed can incorporate those previously void alterations; (b) a general conditional bequest needs to have its date updated; (c) a will contains a description 'my house in Oxford' which the testator has since sold and rebought — republication at a later date can clarify the current property is intended.