There are many reasons why one might consider bringing a will or trust contest.

Perhaps you resided with the decedent and cared for them when they were sick during the final years of their life, which you believe entitles you to a greater inheritance than the other beneficiaries of their estate.

Perhaps you believe the decedent’s new spouse exerted undue pressure on the decedent to disinherit his or her own children and leave them everything instead.

Perhaps you believe the decedent was not of sound mind when they executed an amendment that drastically changed the provisions of their original will or trust.

Your reason for contesting a will or trust is particularly important because the court will not hear a contest that does not meet one of the acceptable grounds for contesting a will or trust. In the first example provided, the beneficiary is seeking to contest the decedent’s will not because the will is invalid but because they believe they are deserving of a greater inheritance than they were left. Contesting a will on this ground alone would be in violation of the rules for contesting a will. The other two examples, however, would likely serve as valid reasons to contest a will or trust.

In this article, we will review and explain the acceptable grounds for contesting a will or trust. If you have questions or would like help with your specific will or trust contest matter, it is recommended you speak with a trust and will contest attorney at your earliest opportunity. If you wait too long, you may lose your right to bring a contest, even if the grounds for contesting a will or trust are valid. 


Why Would You Contest a Will or Trust?

You should consider contesting a will or trust only if you suspect that the document is invalid and you have standing to contest the will or trust (i.e., the new will or trust reduced or eliminated the inheritance you otherwise would have received had it not been executed). 

While we will go into the specific reasons why a will or trust may be considered invalid in the next section, the important distinction to make here is that will and trust contests are not about your personal dissatisfaction with the inheritance you have coming to you from a decedent’s estate or trust; they are about the document not reflecting the true final wishes of the decedent.

What Is “Standing” in Will and Trust Contests?

While meeting the grounds for contesting a will or trust is essential, so is “standing.” Standing means that you have a financial stake in the outcome of the matter. To put it another way, it means that if you were to win your contest, your inheritance would increase. Without standing, you cannot bring a contest. And why contest a will or trust if you have nothing to gain from doing so? Will and trust contests generally come with a high price tag, so if you plan to bring one, you should discuss your plans with an experienced probate attorney before starting the process.

In will and trust contests, persons with standing generally include:


  • Beneficiaries
  • Heirs of the decedent
  • Beneficiaries under a prior version of the will or trust

The court is generally not flexible on the issue of standing, so if you do not fall under one of the categories listed above, it is unlikely you will be able to bring a contest.

What Are Acceptable Grounds for Contesting a Will or Trust?

Challenging a will or trust is usually not easy, as the court tends to default to upholding the final wishes of the decedent as they are stated in their most current will or trust. Nevertheless, if it can be proven the provisions of the document are invalid based on a recognized ground, the court may order for the document to be voided, which would mean the decedent’s assets will either be distributed to their heirs in accordance with the state’s intestate succession statutes or to beneficiaries under a prior valid version of the document if the decedent had executed one.

The court allows the following grounds for contesting a will or trust:


  • Undue Influence
  • Lack of Capacity
  • Elder Abuse
  • Fraud
  • Forgery
  • Lack of Due Execution
  • Mistake
  • Revocation 

In the following subsections, we will delve into what each of the grounds for contesting a will or trust means as well as what kind of evidence is needed to prove them.

Undue Influence

Undue influence takes place when a person uses a position of trust and confidence to their advantage by influencing another person to do something they would not otherwise do. In the context of will and trust disputes, undue influence arises when excessive persuasion is used to convince a person to change their estate plan. 

Many undue influence cases involve children, surviving spouses, caregivers, and fiduciaries because they are typically engaged in trusting relationships with elders. Most of the time, it will be up to the person bringing the trust or will contest to prove that undue influence played a role in the will or trust being signed. 

Proving Undue Influence

To determine whether undue influence could have played a role in the creation or execution of a will or trust, the court will generally consider the following factors: 


  • The vulnerability of the victim (e.g., Was the victim suffering from a condition that impaired their cognitive function?) 
  • The influencer’s apparent authority (e.g., Was the influencer in a position of authority over the decedent by being their power of attorneytrustee or conservator?
  • The actions and tactics used by the influencer (e.g., Was the influencer involved in the preparation of the new will or trust?)  
  • The fairness of the result (e.g., Did the influencer manage to significantly increase their inheritance at the cost of the other beneficiaries’ inheritances being drastically reduced?) 

Presumed Undue Influence

When a decedent makes a gift to a fiduciary, the court generally presumes undue influence, causing the burden of proof to shift from the contestant to the fiduciary who is being accused of undue influence. Caregivers, drafters of wills and trusts (and their family members, partners, cohabitants and employees), and fiduciaries of the decedent who transcribe the will or trust or call for its transcription can fall under this category.

The reason undue influence is presumed in such cases is simple: These categories of persons typically had enough access to the decedent to persuade them to make drastic changes to their will or trust and were engaged in close personal or fiduciary relationships with the decedent, which placed them in a position of trust. 

As an example, a caregiver might convince the decedent that they are the only ones who care about them since their family never visits. Once this idea has been drilled into the decedent’s head, the caregiver may unduly influence the decedent to alter their will or trust to leave them their home, even though the decedent had always intended to leave their home to their family. If the decedent’s family proceeds to bring a will or trust contest, it may be up to the caregiver to prove they did not commit undue influence to compel the decedent to leave them this substantial gift.   

But there is also another presumption that can apply even if the person accused of undue influence is not a caregiver or another type of fiduciary. If all the following conditions are met, undue influence can be presumed:


  • There was a confidential relationship between the decedent and the person suspected of undue influence. 
  • The person suspected of undue influence actively participated in preparing or signing the will or trust. 
  • The person suspected of undue influence profited from the will or trust. 

If you are unsure about whether undue influence played a role in the preparation or signing of your deceased loved one’s will or trust, it is best to discuss the facts of your case with a qualified trust and estate attorney

Lack of Capacity

It is common in will and trust contests for the mental capacity of the elder at the time of execution to come into question, either because they were suffering from impaired cognition due to old age or dementia, or from other mental health issues or disabilities. Because trusts are generally more complex than wills, the competence required to sign a trust is usually greater than the competence required to sign a will.

When using lack of capacity as one of the grounds for contesting a will or trust, it is important to remember that your word alone will not suffice. The court will likely rely on evidence (e.g., medical documentation) and testimony from medical experts and others close to the decedent to determine whether the decedent did in fact lack capacity. 

Capacity to Sign a Will

For a will to be valid, a person must have what is called testamentary capacity. A lack of testamentary capacity would mean the testator does not understand: 


  • The nature of the act (i.e., that a will is being created) 
  • The nature and worth of their property 
  • Who their family members are and anyone else whose interests may be affected by the document 

To prove the decedent lacked the requisite capacity to sign a will, the contestant will need to demonstrate the testator was not of sound mind when signing their will. To do this, the contestant may wish to speak with the decedent’s physicians, caregivers and anyone else who was close to the decedent and can provide insight into their mental state.

Capacity to Sign a Trust

Because trust instruments tend to be more complex than wills, a higher level of capacity, known as contractual capacity, may be required to sign a trust.  

Whereas testamentary capacity has to do with a person’s ability to understand the nature of the document they are signing, the nature of their property, and their relation to beneficiaries, contractual capacity requires that the person not only meet the requirements for testamentary capacity but also understand the future impact of their decisions as well as available alternatives. In general, for a person to possess contractual capacity, they must be able to grasp: 


  • The full implications of the rights and responsibilities affected or created by their decisions 
  • The probable outcomes for themselves and anyone else who will be affected by their decisions 
  • The risks and benefits of their decisions, as well as any alternatives that exist to them 

In order to prove that the decedent lacked the requisite capacity to execute a trust document, you must prove the decedent suffered from a deficit in mental functions that impaired the decedent’s ability to execute the trust instrument.

Elder Abuse

It is an unfortunate reality that elder financial abuse often goes hand in hand with undue influence. As loved ones grow older, they may start to experience mental and physical limitations, making them vulnerable to abuse as people come into their lives to “help” them.  

When evidence suggests elder abuse may have taken place for the purpose of altering the contents of a will or trust, a will or trust contest can likely be brought to invalidate the document. For example, if it comes to light the new girlfriend of a decedent withheld the decedent’s medication or food to compel them to change their will or trust to favor them, a will or trust contest would be warranted.

If the alleged abuse financially harmed the estate or trust, not only can the assets that were lost be recovered from the abuser but damages may be recovered from the abuser as well. Also, If the abuse is successfully proven, the court may move to invalidate the part of the will or trust that names the abuser as a beneficiary. 


Generally, to set aside a will or trust based on fraud, it must be proven the decedent was intentionally deceived, coerced, or tricked into executing the will or trust. Fraud typically falls under one of two broad categories: fraud in the inducement and fraud in the execution.  

Fraud in the Inducement

Fraud in the inducement occurs when a decedent understands they are making a will or trust but the provisions of the document are the result of the decedent having been misled by someone who would ultimately benefit from this act of fraud.

For example, an adult child may lie to their parent about how financially secure their sibling is so the parent will leave them a greater share of the estate or trust. This type of intentional fraud perpetrated by the child for personal gain falls under the category of fraud in the inducement.

Fraud in the Execution

Fraud in the execution occurs when one party deceives another as to the very nature of the contract. This type of fraud may have taken place if the decedent was deceived into executing a document containing misrepresented terms or was lied to about the nature of the document itself. 

For example, if testator or grantor has trouble reading (i.e., they have poor eyesight or are illiterate) and someone informs them that the document they are signing is a power of attorney when they are really signing a will or trust, fraud in the execution has occurred.  


Does the signature of the decedent on a will or trust look like a crude copy? Suspicious circumstances like this may indicate that a forgery has taken place. But the court will not just take your word for it. In most cases, to prove the signature of a decedent on a will or trust is forged, the expert testimony of a forensic handwriting analyst is required.  

The analyst will compare the decedent’s signature on the will or trust with signatures on other documents known to have been signed by the decedent. If they fail to match, the will or trust may have been forged and may be invalidated by the court.

Lack of Due Execution

The grounds for contesting a will can also be based on a lack of due execution, which means the proper legal steps were not followed when the will was signed. California law requires a will to be signed by two “disinterested witnesses” who are physically in the presence of each other. 

While it is rare for issues with due execution to occur when the signing of a will is supervised by an experienced estate planning attorney, the surge of people opting to draft and execute their own wills using estate planning software has made lack of due execution a common ground for contesting a will in modern times. 


The margin is narrow for a will or trust to be invalidated because of a mistake. The most common scenario for applying the defense of mistake is when the decedent mistook the document they were signing to be something other than a will or trust. 

A distinction should also be made between trying to invalidate a will on account of a mistake and trying to invalidate a trust on account of a mistake, because to invalidate a will on account of a mistake is much more challenging than invalidating a trust on account of a mistake. 

To invalidate a trust on account of a mistake, it must be proven the grantor executed the trust by mistake or was mistaken about the laws surrounding the execution of a trust. The only way to invalidate a will on account of a mistake is to prove the decedent had been mistaken about the document they were signing; in other words, they did not know they were signing their will into effect. 


A will or trust is invalid if it was revoked by the person who created it.  

There are many reasons why a person may choose to destroy, modify or replace a will or trust. For example, the decedent may have gone through a divorce, remarried, or had a child. When a person dies, if multiple wills surface because they were not revoked properly, it can create confusion for beneficiaries, who may have to engage in expensive legal battles to get the inheritances they are due. 

For a will to be revoked, it typically just needs to be destroyed, replaced or modified; however, for a trust to be revoked, the process is a little more complicated. If you are seeking to revoke an estate planning document, it is best you speak with a qualified estate and trust attorney to ensure you are taking the proper steps.

Need Help Determining Whether Your Case Meets the Grounds for Contesting a Will or Trust? Keystone’s Will and Trust Contest Attorneys Can Help.

If you are unsure whether you have grounds to contest a will in Calfornia or the grounds to contest a trust in California,  Keystone Law Group’s experienced estate and trust attorneys can help. Our trust and will contest attorneys specialize in probate litigation. They have years of experience handling complex probate matters for clients across California seeking to challenge a will or trust. Call us today to schedule your complimentary consultation.