A codicil is a supplement to a previous will that adds to, modifies, amends, or revokes one or more provisions of the earlier will. Laws regarding codicils vary from state to state and in some states a codicil may not replace an earlier will—but in some states it may.
In Wyoming, a codicil is recognized as a legal instrument that can be used to make changes to an existing will. It must be executed with the same formalities as a will, which means it needs to be in writing, signed by the testator (the person making the will), and witnessed by at least two individuals who are present at the same time and understand that the document is intended to be a will or codicil. A codicil can add to, subtract from, or otherwise modify the terms of the will it supplements. It does not replace the original will but is read in conjunction with it. If there are any conflicts between the original will and the codicil, the provisions in the codicil take precedence. However, it is often advisable to create a new will if there are substantial changes to be made, to avoid any potential confusion or legal disputes after the testator's death.