Originally published: 12 November 2021 | Last updated: 12 March 2026
TL;DR. How a Will Works
A written legal document called a Will establishes how your property will distribute after you pass away. The document requires you to create it during your mental fitness period while two independent witnesses must observe your signature and the document activates after your death. A person can modify their Will whenever they want during their life but marriage causes their Will to become invalid. The ten fundamental principles of Will execution help you achieve your desired results.
How Does a Last Will and Testament Work?
People have many incorrect beliefs about the operational system of Wills. People assume their assets will automatically pass to their spouse, or that a verbal instruction to a family member is sufficient. The two statements do not represent the truth. Here are 10 essential principles that explain exactly how a Will functions under UK law.
1. Does a Will Have to Be Written Down?
Yes. A Will should exist as a written document according to the Wills Act 1837. The law prohibits people from using recorded audio or video files or phone or computer storage or spoken communication as valid evidence for creating a Will. The rule continues to exist as an unbreakable law which applies to the twenty-first century.
The law provides only a few narrow exceptions. The law allows active military personnel to create verbal Wills under specific conditions which apply to their situation. However, for the general public in England and Wales, a Will must be a physical written document.
The process of writing a Will allows for three options which include handwriting or typing or using an online service but the final document needs to exist as a physical paper document. The method of drafting does not matter. A proper Will needs to exist as a written document which contains your signature and witness signatures.
2. When Does a Will Take Effect?
A Will only takes effect after you die. People seem to misunderstand this particular point which forms the basis of estate planning. Your Will does not possess any legal authority from the moment you create it until your death occurs. You can:
Sell, give away, or spend any asset mentioned in your Will
Change your mind about beneficiaries at any time
Write a completely new Will whenever you choose
Revoke your Will entirely
Your Will is essentially a set of instructions that only activates at the moment of your death. The document remains inactive until this point because you lack any legal authority to control your assets.
3. Do You Need to Be Mentally Competent to Write a Will?
Yes. You must have “testamentary capacity” when you write and sign your Will. This means you must:
Understand that you are making a Will
Understand the general extent of your assets
Understand who might reasonably expect to benefit from your estate
Not be suffering from any mental disorder that affects your decision-making
The rule demands people to wait until their final days before they start their journey. The time for Will preparation ends when someone develops dementia or becomes an intensive care patient. You need to understand that holding a Lasting Power of Attorney does not give you permission to create Wills for other people. The evidence for creating your Will today stands as the most powerful reason to avoid waiting any longer.
4. Can You Change a Will After Signing It?
Yes. You can change your Will at any time, as many times as you wish, provided you remain mentally competent. Two main methods exist for handling this process:
A codicil serves as a formal document which modifies particular parts of a Will through the same signature and witness requirements as the original document. The process of creating a new Will automatically cancels all previously existing Wills.
With an online service like LegalWills.co.uk, updating your Will is simple and cost-effective. The KeyHolder plan offers members unlimited update access without any additional payment.
5. How Must a Will Be Signed and Witnessed?
The Wills Act 1837 establishes three basic requirements which must exist for a Will to become valid:
The testator (person making the Will) needs to sign their Will face-to-face with two witnesses who must also be present at the same time
The two witnesses need to stay together throughout the entire process of signing the Will which they must do while staying in the presence of the testator
The witnesses who sign the Will must be at least 18 years old and they should not receive any benefits from the Will nor should they be married to someone who receives benefits. A beneficiary who watches the Will process will lose their right to inherit under Section 15 of the Wills Act. For detailed guidance, see our article on signing your Will.
6. Does Marriage or Divorce Affect a Will?
Yes, significantly:
Marriage automatically revokes any existing Will in England and Wales (unless the Will was made in contemplation of that specific marriage)
Divorce does not revoke the entire Will, but any appointment of the former spouse as Executor or beneficiary is treated as if they had died on the date of the decree absolute
This means you must write a new Will after getting married. After divorce, you should review and update your Will to reflect your new circumstances, even though it is not automatically revoked.
7. Can You Disinherit Someone in Your Will?
In England and Wales, you have testamentary freedom. You have the freedom to distribute your estate to any individual you want. However, the Inheritance (Provision for Family and Dependants) Act 1975 allows certain people to challenge a Will if they believe they have not received reasonable financial provision. People who can make a claim include:
Spouses and civil partners
Former spouses who have not remarried
Children (including adult children)
Anyone who was being maintained by the deceased
Cohabitants who lived with the deceased for at least two years
8. What Happens During Probate?
Your Will must undergo probate after your death to become legally valid for estate administration. Your Executor needs to submit an application to the Probate Registry which grants them legal power to handle your estate. The Executor needs this Grant of Probate to collect all your assets and determine their worth.
The Executor needs to use your estate funds to clear all debts and taxes and funeral costs. The remaining assets in your estate will distribute according to the instructions which you included in your Will.
You need to select a trustworthy Executor because this choice stands as one of the most vital decisions which your Will requires.
9. What Cannot Be Distributed Through a Will?
Not all assets pass through your Will. The following are typically distributed outside the Will:
Asset Type
How It Passes
Joint tenancy property
Property ownership transfers to surviving joint tenant through automatic process.
Life insurance with named beneficiary
The named beneficiary will receive the policy benefits directly through this designation.
Pension death benefits
At discretion of pension trustees (your nomination is considered)
Assets held in trust
According to the trust terms
Your estate plan will become complete when you identify all assets which do not need to go through your Will.
10. What Happens If You Die Without a Will?
The rules of intestacy determine how your estate will be divided when you pass away without creating a valid Will (intestate). These fixed rules may not match your wishes. The following results occur when people fail to register their partnerships:
Unmarried partners receive nothing
Your spouse may not inherit everything. The law requires estates which exceed £322,000 to distribute their assets among children.
Close friends and favourite charities receive nothing
The court appoints an administrator. You have no say in who manages your estate
Frequently Asked Questions
Do I need a solicitor to write a valid Will?
No. There is no legal requirement to use a solicitor. A reputable online Will service creates legally valid documents for a fraction of the cost. A solicitor needs to handle estate matters which include business assets and overseas property and trust management.
Can I write a Will on a piece of paper?
Yes, provided it is properly signed and witnessed. People who create handwritten or DIY Wills establish documents which contain numerous mistakes that others will probably challenge in court. The online service provides users with guided instructions which help them fulfill every legal requirement.
How often should I review my Will?
You must review your Will during every major life transition which includes marriage and divorce and birth and death and when your assets experience major changes and you should review it every three to five years. The LegalWills.co.uk KeyHolder plan enables members to make free updates which take only a few minutes to complete.
He has over 20 years of experience helping people to write their Will and other estate planning documents. He has been interviewed by many of the major news media outlets and has contributed to articles in most leading publications. He has also contributed to a number of financial planning books.
Throughout his career, Tim has written extensively on the subject of Will writing and estate planning.
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