It’s never easy to know that a beloved family member, maybe even a parent, left you out of their will. You even may wonder if you should contest your loved one’s will to get your share.

However, you can’t contest a will just because you don’t like its terms. Contesting a will makes sense only when it could be legally invalidated for one of the following reasons:

The will doesn’t meet New York’s legal requirements.

In New York, as in most states, a will must be written by someone over the age of 18 and by someone who is of sound mind. Also, two witnesses must see the testator (the person who completed the will) sign it or witness the testator acknowledge that the will is theirs.

Also, in New York, only military service members in an armed conflict can have oral or handwritten wills. And handwritten wills need to be completely written in the testator’s handwriting.

The testator lacked the mental capacity to sign the will.

When someone signs a will, they need to be able to understand the nature of their assets. They need to understand the legal implications of signing the will. Often, those suffering from early signs of dementia still have the mental capacity to sign a will. If they understand what they are signing and the will’s details, the will is considered valid.

In cases where someone’s mental capacity is in question, the witnesses who saw the will’s completion have to offer their assessment of the testator’s mental capacity. Often, a will only can be invalidated if a doctor’s diagnosis confirms mental incapacity within days of the will’s signing.

The testator was unduly influenced.

Elderly people often are easy to influence and con. Sometimes, someone who wants part of an elderly person’s assets will put undue influence over the testator when they are writing their will. This includes consulting the testator’s attorney about key aspects of the will, paying for the will or isolating the testator from their family and friends. Undue influence goes beyond someone nagging, harassing or threatening a testator, so it’s also difficult to prove in court.

The will was created by fraud.

In this case, the testator is tricked into signing the will. Sometimes, the testator is told the will is a power of attorney document or a deed and they sign it without realizing the document is a will.

Contesting a will can take a long time and be expensive. You should consult with an estate planning attorney if you feel your loved one’s will could be invalidated because of one of the reasons noted in this article. An attorney can advise you how likely invalidating the will is.