When Does a Will Not Hold Up in Court?

IMPORTANT: This guide is for general educational purposes for U.S. adults with relatively simple finances. It is not legal, tax, or financial advice. HeirLight is not a law firm and does not provide legal advice. Laws vary by state; consider consulting a licensed attorney about your specific situation.
A lot of worry about online wills comes down to one quiet question: will this actually hold up? Here's the calm, accurate version.
Quick answer: A will usually fails in court for one of four reasons: it wasn't signed and witnessed properly, the person lacked the mental capacity to make it, it was the product of fraud or forgery, or someone unfairly pressured the person into it (undue influence). A will can't be thrown out just because an heir is unhappy with their share. There has to be a real legal ground, and the person challenging it has to prove it.