Type 1: Revocation by Act. A revocation by act is when you take a specific action to revoke a previous will you’ve written. The most common way to do this is to write a new will that contains a clause that specifically revokes the old will. You may also physically destroy a will to revoke it, such as by burning it or ripping it up.
Type 2: Partial Revocation. A partial revocation is usually carried out by creating either a new will or a codicil that states part of the old will is no longer valid. Many states do not allow for a partial revocation by physical act, so simply crossing out the portions of your will that you no longer wish to apply may not be enough to revoke that part.
Type 3: Revocation by Presumption. A person who makes a will and later dies, leaving no evidence of the will for anyone to find, may have his or her will revoked by presumption. The presumption is that a testator knows the will is important and if it is not easily found, the testator must have destroyed it before he or she died.
Type 4: Revocation by Operation of Law. Most states have laws that automatically revoke portions of your will in certain situations. For example, if you get divorced or have your marriage annulled, any portion of your will that refers to your spouse, or his or her relatives, is often automatically revoked.