When you and your family are dealing with the death of a loved one, there's one thing you don't want to have to deal with: a protracted battle over the will. Unfortunately, there are times when it's unavoidable. Perhaps the person managing the estate is misappropriating assets, refusing to provide financial accountings or you believe they may not be fulfilling their duties in one way or another.
In many cases, you can challenge a will. However, the courts only allow "interested persons" to challenge. What exactly does that mean, though? An "interested person" is someone who was an intestate heir, a beneficiary of a previous will or a beneficiary of a newer will. This will typically be a spouse, a child, an heir, a creditor or anyone who has a legitimate property right.
The legal condition at play here is one of "standing." In other words, the courts will recognize your right to challenge a will if you stand to gain, would have stood to gain or stand to lose something based on the interpretation of the will.
There is also the matter of "no contest" clauses, which can exclude someone (effectively disinherit them). However, even wills with "no contest" clauses can be legally challenged.
If you feel you have a valid argument over a loved one's will, one of the first steps you can take is sitting down with an attorney with experience in estate law. He or she will be able to look at the will, hear your side of things and determine if you can challenge it.