Not everyone can contest a will. A lawsuit brought to challenge the validity of a last will and testament can only be filed by certain people who would be personally and financially affected by the will's terms if it were to be accepted by the court as it is. In legal terms, these people are said to have "standing."
An heir-at-law is someone who is so closely related to the decedent that she would have received a share of the estate if the decedent had died without a will. Heirs-at-law have standing to contest a will.
Property passes to heirs-at-law in a process known as "intestate succession" when someone dies without a will. In most states, this means his spouse or direct descendants inherit first. Direct descendants include his children or grandchildren. Parents and more distant family members, such as siblings, would only inherit if the decedent wasn't married and left no living children or grandchildren.
If a decedent was survived by three children but only two are provided for in his will, the third child should have legal standing to file a will contest. But this doesn't necessarily mean she would win the case. She can't challenge the will simply because she has standing and she wasn't named in it. She must have cause.
This means that she would have to establish to the court's satisfaction that the deceased didn't intentionally cut her out of the will, or that will isn't valid for some other reason. Perhaps the deceased was under duress or was mentally incapacitated at the time he wrote it.
The will might subsequently be thrown out due to its invalidity, and the estate would then be distributed as though the deceased had died intestate or without a will.
Beneficiaries and Fiduciaries in a Prior Will
Any person or entity named in an older will would have sufficient legal standing to contest a more recent will if he has subsequently been cut out of the recent document. He would also have standing if his share of the estate was reduced.
Likewise, if the individual was named as fiduciary or executor of the estate in the first will, but he's been replaced in a subsequent will, he should have adequate standing to challenge the more recent last will and testament.
The same caution applies. These people would have to establish that the subsequent will is invalid for some reason.
Who Can't File a Will Contest?
You most likely don't have legal standing to file a will challenge if you weren't named as a beneficiary in another will, or if you're not an heir-at-law. This is the case even if you suspect that the will is invalid.
Minors typically cannot contest a will because they lack the right to initiate any legal proceeding until they reach the age of majority. Most states permit a parent or guardian to challenge a will on a child's behalf, however.
"No Contest" Clauses
A potential complication is that some wills include "no contest" clauses. These state that beneficiaries will lose the inheritance the will gives them if they unsuccessfully challenge it, losing the will contest in court. Otherwise, the court's verdict would prevail.
Of course, a beneficiary really has nothing to lose by challenging the will if she's been cut out of it entirely.
Not all states will enforce no-contest clauses, so check with an attorney if you have reason and standing to contest a will that contains one of these clauses.
What Should You Do?
Will contests are a complex area of law. Consult with a lawyer who specializes in this type of probate matter to find out if you have legal standing and if you have possible grounds—a supportable reason why the will should be overturned.