Can One Sibling Inherit Everything in California?

One child gets everything. Everyone else gets nothing. Is that legal?

It depends.

In California, being someone’s child doesn’t guarantee that you will inherit from them. A parent can leave unequal amounts to their children. They can even disinherit six children and leave everything to one.

Is it fair? Probably not.

What I have learned since entering probate litigation is that unfair does not automatically mean illegal.

So, Yes, One Sibling Can Inherit Everything

I think this is one of the hardest things for families to accept after a parent dies. We often assume children have some automatic right to an equal share of a parent’s property.

But families are not always equal, and neither are inheritances.

A parent may decide that one child needs more financial help. One child may have served as a caregiver. A parent may be estranged from another child. Sometimes a parent simply makes a decision the rest of the family does not understand or agree with.

The fact that one sibling received everything does not, by itself, prove that something illegal happened.

If a parent knowingly and voluntarily created a valid trust or will leaving everything to one child, the other children’s anger or sense of unfairness does not, by itself, invalidate the document.

But the key words are “knowingly” and “voluntarily.”

**Click to watch: Why “unfair” isn’t always illegal in probate court.**

When Circumstances Might Change Things

Instead of focusing only on whether the inheritance was divided equally, another question may be more important:

What was happening when the document was created?

Was the parent experiencing cognitive decline? Did they understand what they were signing? Had they recently become seriously ill? Was one person controlling access to them? Did one person arrange the estate planning appointment? Was the parent dependent on the person who ultimately received everything? Did the new estate plan represent a sudden departure from what the parent had said or done before?

None of those facts automatically proves that a trust or will is invalid. But depending on the circumstances and available evidence, they may lead families to ask whether legally recognized issues such as lack of capacity or undue influence were involved.

That was the question in my family.

Why We Started Asking Questions

Our concern wasn’t just because my brother received everything. If my mother knowingly and independently decided to leave everything to him, that would have been her decision to make.

What concerned us were the circumstances surrounding the trust.

My mother was diagnosed with end-stage renal disease in April 2015. My brother was the only one present at that doctor's appointment. The following month, a trust was created that disinherited six of her seven living children and left everything to that one brother. We knew nothing about it until about two months after she died.

The timing raised questions for us. As we looked more closely, my mother’s health and other circumstances gave us more reasons to question the validity of the documents.

As I began researching California probate law, I learned about legal grounds such as lack of capacity and undue influence. I also learned that my mother’s illness did not, by itself, mean she lacked capacity. And the fact that my brother received everything did not, by itself, prove that she had been unduly influenced.

We needed facts and evidence that connected our concerns to legally recognized grounds.

Suspicion Was Only the Beginning

I think this was one of the harder lessons for me. Something can feel wrong without giving you a legal basis to challenge it. One sibling receiving everything may be shocking, unfair, or completely unexpected, but the distribution alone does not prove lack of capacity or undue influence.

For me, suspicion was only the beginning. It wasn't the answer.

I had to learn whether we had standing, whether we were within the applicable deadline, whether our concerns fit legally recognized grounds, and what evidence might support them.