What Is a Codicil?

A codicil is a separate document, but it operates as an amendment to a specific will, so it needs to identify that will clearly, for example by date, and set out precisely what is being changed. It might update an address, replace an executor who is no longer able to act, add a new small gift, or remove a gift that no longer applies.

Crucially, a codicil does not stand alone. It only makes sense read alongside the will it amends, so both documents need to be kept together and both need to be produced when the estate is administered.

A codicil must be signed by the person making it and witnessed by two independent witnesses in the same way as a will, following the same rules under the Wills Act 1837. It is not a casual note attached to the will, and an unwitnessed amendment, even if it is on a separate piece of paper, will not be effective.

Because of this, drafting a codicil correctly takes just as much care as drafting a will, which is part of why many people question whether it is really less effort than starting again with a full new will.

In modern practice, particularly with straightforward, affordable will writing services available, many people find it easier to make an entirely new will rather than a codicil, even for a fairly small change. A new will is a single, self-contained document, which reduces the risk of the codicil being separated from the original will or overlooked by executors.

Multiple codicils accumulated over the years can become genuinely difficult to follow, since each one needs to be read in the context of the original will and any earlier codicils, increasing the chance of a mistake or an ambiguity being missed.

A codicil can still be a reasonable, quick option for a very small, one off change to an otherwise recent and satisfactory will, such as correcting a spelling error in a name or updating an executor's address. Even then, it is worth weighing the convenience against the fact that a new will, using a service such as My Posh Will, can often be produced with similarly little effort while giving you a clean, current document.

If in doubt, or if more than one change is needed, a new will with a clear revocation clause is generally the safer route.

If a codicil genuinely is the right choice, the process should still be treated with care. Identify the will being amended clearly, by date and, if helpful, by referring to its opening words. Set out precisely what is being changed, using clear, unambiguous wording rather than vague references to 'the gift to my daughter' if there is more than one daughter or more than one gift involved.

Sign the codicil and have it witnessed by two independent witnesses, present together, exactly as you would for a will, and keep the codicil physically attached or clearly cross-referenced to the original will so the two documents are never separated. Tell your executors that a codicil exists alongside the will, since a codicil found after probate has begun can cause serious delay.

If you decide to have a codicil prepared professionally, it helps to bring the original will you want to amend, a clear written note of exactly what you want to change, and the up to date names and addresses of anyone newly involved, such as a replacement executor. Bringing the original document, rather than a copy or your memory of its contents, avoids the risk of a codicil accidentally contradicting wording it was never checked against.

It is also worth mentioning to the solicitor whether you have made any other changes informally, or believe there might be more than one earlier codicil, so they can check the full picture before drafting anything new.