Under Missouri law, you can revoke a Will be destroying it, canceling it, or by creating a new Will.
When a client has an existing Will (plenty of course do not—for many clients this is their first estate plan), they frequently ask what will happen to their old Will, if they create a new one.
Under Missouri law, you can revoke a Will by destroying it*, canceling it, or by creating a new Will. That last option—creating a new Will—is the most common way we revoke an old Will.
When you have a new Will drafted, your old Will is no longer valid, so long as the newer Will exists. If for some reason you want the old Will to “kick back in,” all you would have to do would be cancel or destroy the current Will.
In short: the newest Will trumps all prior Wills.
*Destroying a Will requires the intent of the Testator (person who made the Will). If a Will were destroyed by accident or by a third party, any existing copies of the Will could still be proved valid.