How to change a will: codicils, new wills and what marriage and divorce do

Can you change a will by writing on it?

No, not once it has been signed and witnessed. Section 21 of the Wills Act 1837 says that crossings out, words added between the lines and other alterations made after a will was signed have no effect unless the alteration is itself executed in the same way as the will, which in practice means you and two witnesses signing beside the change or beside a note in the will that refers to it. GOV.UK puts it plainly in its guidance on updating your will, which says you cannot amend a will after it has been signed and witnessed.

The section makes a narrow exception where the original wording has been blotted out so thoroughly that it can no longer be read, but that is not a safe way to change anything, because it leaves your executors guessing about what you meant. MoneyHelper's guide to changing your will likewise says you should not alter the original document by writing on it or adding anything to it, so the reliable routes are a codicil or a new will.

What is a codicil and when does it make sense?

A codicil is a separate document that changes part of your will whilst leaving the rest of it in place. Section 1 of the Wills Act says the word "will" extends to a codicil, so a codicil has to meet the same formal requirements as the will itself: it must be in writing and signed by you in the presence of two witnesses who are there at the same time, and each witness then signs in your presence. MoneyHelper advises using witnesses who are not beneficiaries, because under section 15 of the Act a gift to a witness, or to a witness's husband, wife or civil partner, fails even though the document stays valid. Our guide to who can witness a will covers those rules in detail.

MoneyHelper suggests using a codicil only for very small changes, such as changing an executor or adding a legacy, and says a new will is usually better if you are changing several parts of the will. GOV.UK says there is no limit on how many codicils you can add, although each one is another document your executors have to find and read alongside the will. MoneyHelper suggests keeping any codicil with the original will, because a codicil kept separately is easily lost, and our guide to where to keep your will sets out the storage options.

When is a new will better than a codicil?

A new will is usually the better route once the change goes beyond a detail, because it leaves your executors with one clear set of instructions. GOV.UK recommends making a new will for major changes, and a new partner or a different split of your estate between your children would normally fall into that category. Starting again also lets you deal with parts of the old will that have quietly gone out of date, such as a gift of something you no longer own.

A new will has to meet every formal requirement afresh, so it needs your signature and two independent witnesses just as the first one did, and our guide to writing your own will explains the rules and the mistakes that most often cause problems. GOV.UK suggests getting advice where a will is not straightforward, for example where you share property with an unmarried partner, own a business, have property overseas or expect that a second spouse and children from an earlier marriage may both make a claim.

How do you revoke an old will?

A will can only be revoked in the ways section 20 of the Wills Act 1837 allows, which are a later will or codicil, a written document declaring that you revoke it and signed and witnessed like a will, or burning, tearing or otherwise destroying it with the intention of revoking it. The destruction has to be carried out by you, or by someone else in your presence and at your direction, so a will destroyed by another person acting on their own initiative is not revoked in law.

The simplest way to revoke an old will is a new will that says so, and GOV.UK says a new will should state that it revokes all previous wills and codicils, and MoneyHelper adds a caution for anyone with a separate will dealing with property abroad, because revocation wording that is too broad can cancel that will by accident. GOV.UK suggests destroying the old will by burning or tearing it up, which is best left until the new one has been properly signed and witnessed, since until then the old will is the only valid one you have.

Does marriage revoke a will?

Yes. In England and Wales getting married or forming a civil partnership revokes any will you made before it. Section 18 of the Wills Act 1837 sets out the rule for marriage and section 18B applies the same rule to civil partnerships, and GOV.UK states it simply: getting married cancels any will made before the marriage. If you marry and do not make a new will, your estate is likely to pass under the intestacy rules rather than under the will you thought you had, and our guide to the intestacy rules sets out who inherits in that situation.

There is an exception for a will made with a particular marriage in mind. If it appears from the will that, when you made it, you were expecting to marry or form a civil partnership with a particular person and intended the will to survive that, the marriage or civil partnership to that person does not revoke it. The intention has to appear from the will itself, which is why a will made before a wedding needs to say so expressly and name the person you are expecting to marry.

No other change in your life revokes a will in England and Wales, because section 19 of the Act says a will cannot be revoked by any presumption arising from a change in circumstances, so having children or moving house leaves it fully in force until you change it.

The Law Commission's report on modernising wills law, published on 16 May 2025, recommended abolishing revocation by marriage or civil partnership, partly to address predatory marriage, but that is a recommendation only, because the government has said it is considering the report and will respond in due course without giving a date, so the current rule still applies to anyone marrying today.

What does divorce do to a will?

Divorce does not revoke a will, but it removes your former spouse from it. Under section 18A of the Wills Act 1837, once the marriage is dissolved or annulled, any appointment of your former spouse as executor or trustee, and any gift to them, takes effect as if they had died on the date of the divorce, unless the will shows you intended otherwise. Section 18C applies the same rule when a civil partnership is dissolved or annulled, and the Children Act 1989 separately cancels an appointment of a former spouse or civil partner as guardian of your children, again unless the appointment shows a contrary intention.

The practical effect depends on how the will was drafted, because a backup beneficiary named for the gift will take it, whereas if there is no backup and the gift was of your whole estate, that part may pass under the intestacy rules. Section 18A also leaves intact your former spouse's right to ask the court for financial provision from your estate under the Inheritance (Provision for Family and Dependants) Act 1975.

What about separation?

Separation on its own has no effect on a will. Section 18A only applies once the marriage has actually been dissolved or annulled, and GOV.UK explains that it is the final order (called a decree absolute for divorce applications made before 6 April 2022) that ends a marriage. Until then your spouse keeps everything your will leaves them, and Citizens Advice notes that a separated but still married spouse also inherits under the intestacy rules where there is no will (the exception being a formal judicial separation order, which under section 18 of the Matrimonial Causes Act 1973 removes the spouse from an intestacy but still leaves a will untouched). The same applies if you never married, since a will leaving everything to a partner you have since split up from stays in force because the divorce rule only reaches marriages and civil partnerships. GOV.UK lists separation as one of the changes that should prompt a review, and since a divorce can take months to finalise, separation is often the point at which reviewing matters most.

When should you review your will?

GOV.UK suggests reviewing your will every five years and after any major change in your life, and gives examples including separation or divorce, marriage, having a child, moving house and the death of an executor named in the will. MoneyHelper's list adds grandchildren, the death of someone named in the will, starting a business, buying property overseas and a major change in your medical circumstances.

A review does not always end in a change, because often the will still says what you want and the only thing to confirm is that the executors and guardians you named are still willing to act. An out-of-date will can only be put right after your death if the beneficiaries agree to redirect what they receive, using a deed of variation within two years, which our guide to deeds of variation explains. That is a repair after the event, and a will left unclear by informal changes is more open to challenge, as our guide to contesting a will sets out.

How is it different in Scotland and Northern Ireland?

Scotland has its own law of wills, and the biggest difference is that marriage does not revoke a will there. The mygov.scot guidance on updating a will (updated September 2026) says that getting married or entering a civil partnership does not cancel an existing will, whilst divorce or ending a civil partnership means gifts to your former spouse or civil partner no longer apply. It also says a Scottish codicil must be signed by you, and that a witness needs to sign it as well for it to be self-proving. Scots law also has a rule that England and Wales does not, which HMRC's Inheritance Tax Manual describes: a will that makes no provision for children can be presumed revoked when a child is born afterwards.

Northern Ireland has rules close to those in England and Wales but under its own legislation, the Wills and Administration Proceedings (Northern Ireland) Order 1994, which revokes a will on marriage or civil partnership with the same exception for a will made in expectation of a particular marriage and removes a former spouse or civil partner from a will after divorce or dissolution. nidirect's guidance on making a will says you can change an existing will with a codicil or by making a new one, and suggests reviewing it every five years and after separation, marriage or divorce.

What to do next

1. Read your current will and note anything that no longer reflects your wishes, including the people you named to act for you.

2. Decide whether the change is small enough for a codicil or whether a new will would leave a clearer result.

3. If you live in England, Wales or Northern Ireland and have married or formed a civil partnership since making your will, it has probably been cancelled unless it was made in expectation of that marriage, so a new will is needed for your wishes to apply.

4. If you have separated, review the will now rather than waiting for the final divorce order.

5. Sign any codicil or new will in front of two independent witnesses who are present at the same time, and only then destroy an old will you are replacing.

6. Keep the codicil or new will with your other important papers and tell your executors where it is.

After your death, your executors will have to find and tell every bank, utility, insurer and subscription you held, which is far quicker if each review of your will also refreshes a simple list of your accounts kept alongside it. If that work does fall to your family, Legacy Trail's free notification service can contact those private-sector companies for them.