Last Updated on May 27, 2026 by tanya

Are Siblings Allowed to Dispute a Will?

 

About Our Legal Expert: This content is produced under the oversight of Michael Jefferies, First Personal Injury Director, who brings over 30 years of legal experience.

Written by Tanya Waterworth, Digital Content Writer

 

Why You Need a Contentious Probate Solicitor

Disputes over a loved one’s estate can place considerable emotional and financial pressure on families which can lead to inheritance disagreements, but are siblings allowed to dispute a will? Essentially yes, siblings can contest a will, but only if they have valid legal grounds.

Disputing a will falls under contentious probate law and it’s advisable to consult with a solicitor early as time limits can apply and evidence may quickly become stale.

 

When Can Siblings Legally Dispute a Will in England & Wales?

Legally, siblings have the right to dispute a will if they believe:

The will is invalid,

They have been unfairly excluded from the estate, or

They have not been reasonably provided for under the Inheritance (Provision for Family and Dependants) Act 1975.

 

However, being unhappy with the will isn’t enough. A sibling must demonstrate a recognised legal ground for their challenge as courts will require evidence to support any claim.

It is also important to remember that time limits apply. For example, Inheritance Act claims must usually be issued within six months of the grant of probate, making early legal advice crucial.

 

What Are the Valid Grounds for Challenging a Will?

If you are a sibling considering contesting a will, it’s essential to understand the legal grounds available, such as:

Lack of Testamentary Capacity

A will may be invalid if the testator (the person making the will) lacked the mental capacity to understand:

 

The nature and effect of making a will,

The extent of their estate, and

The claims of those who might expect to benefit.

 

You may gather medical evidence, cognitive assessments or witness testimony to prove that a testator did not have the capacity to make a valid will. This is especially if they were an elderly or ill relative.

 

Undue Influence

Undue influence occurs when someone pressures or coerces the testator into making a will that does not reflect their true wishes. This influence is often challenging to prove.

Examples include:

 

Isolating the testator from the rest of the family,

Dominating their decisions, or

Manipulating them into leaving assets to one party at the expense of others.

 

Siblings who suspect foul play often challenge wills on this basis, especially when there is a sudden or unexpected change in the testator’s intentions.

 

Lack of Proper Execution

For a will to be valid in England and Wales, it must comply with the Wills Act 1837. This means:

 

It must be in writing.

The testator must sign it (or direct someone to sign on their behalf).

Signing must take place in the presence of two independent witnesses.

Witnesses must also sign the will.

 

Errors in execution, such as using beneficiaries as witnesses, can render the will invalid. Siblings may challenge the will if they believe these formalities weren’t properly observed.

 

Fraud or Forgery

A will may be disputed if you suspect:

 

Someone forged the testator’s signature,

The will was replaced with another document, or

The testator was misled into signing something they did not understand.

 

Fraudulent activity is serious and can invalidate the entire will. Handwriting analysis, expert evidence and witness statements often play a key role in these disputes.

 

Lack of Knowledge and Approval

Even if a will appears properly drafted and executed, the testator must have understood and approved its contents. If the will contains unexpected provisions or was executed in unusual circumstances, siblings may question whether the testator knew what they were signing.

Grounds may include:

 

Language barriers,

Visual impairment,

Reliance on others to prepare documents,

Suspicious or rushed signing processes.

 

Inheritance (Provision for Family and Dependants) Act 1975 Claims

Siblings can also dispute a will by making a claim under the Inheritance Act, if they believe the will fails to provide them with reasonable financial provision.

Typically, siblings are not always automatic applicants under the Act. But they may be eligible if they:

 

Were financially dependent on the deceased,

Lived in the same household and were treated as part of the family, or

Can show the deceased had an obligation to maintain them.

 

This type of claim does not challenge the validity of the will itself. Essentially, it asks the court to redistribute the estate to ensure fairness.

 

Why Siblings Commonly Dispute Wills

Inheritance disagreements between siblings are more common than many people realise. Typical disputes may involve:

 

Unequal distribution of the estate

Exclusion of one or more siblings

Concerns over another sibling’s influence over the deceased

Late-life changes to the will that appear suspicious

Confusion or conflict caused by blended families

Breakdowns in communication or unresolved family tensions

 

Even small inconsistencies can spark serious legal conflict.

 

Why You Need a Contentious Probate Solicitor

Challenging a will is legally complex and consulting a specialist contentious probate solicitor can make a significant difference to the outcome of your case.

Here’s why expert legal guidance matters:

 

1. They Assess the Strength of Your Case Early

Not every dispute is worth bringing a claim. Your solicitor will:

 

Evaluate the evidence,

Identify the most appropriate legal grounds,

Outline your chances of success, and

Protect you from unnecessary costs.

 

Early assessment is crucial in avoiding missteps or missed deadlines.

 

2. They Gather Critical Evidence

Contentious probate claims may often rely on specific evidence, including:

 

Medical records,

Witness statements,

Handwriting analysis,

Solicitor’s file notes, and

Financial documents.

 

Your solicitor will be experienced in these claims and knows exactly what to obtain, how to obtain it, and how to present it effectively.

 

3. They Navigate Strict Deadlines

Some probate claims have strict time limits, especially Inheritance Act claims. Missing a deadline can prevent you from pursuing your case altogether. A solicitor ensures every step is completed correctly and on time.

 

4. They Protect Family Relationships Where Possible

A skilled contentious probate solicitor will aim to resolve disputes through mediation and negotiation before resorting to court proceedings. This reduces stress, can help to preserve family relationships, and typically results in faster, more cost-effective outcomes.

 

5. They Improve Your Chances of a Successful Outcome

Probate litigation requires specialist knowledge. A contentious probate solicitor understands how to judges interpret will disputes and how to build persuasive arguments. Therefore, have an experienced contentious probate lawyer on your side can significantly increase the likelihood of achieving a fair and just resolution.

 

Get Help Today – Free Consultation

Whether you believe the will is invalid or you feel you’ve been unfairly excluded from a loved one’s estate, it’s essential to act quickly and seek professional advice.

Reaching out to a trusted claims company can make all the difference during this emotional time. We will ensure you receive all the support you need. 

We partner with law firms which offer a range of fee structures, including ‘No Win, No Fee’ agreements along with other flexible funding – speak to our team to find out more.

Call us at 0333 358 2345 or contact us online at First Personal Injury and we’ll call you back.