The Illinois Affidavit as To Copy of Will is a type of document used in the state of Illinois to prove that the copy of a will in question is an exact copy of an original will. The affidavit must be signed and sworn to by the custodian of the original will or an authorized person who is familiar with the original will. It must also include the name of the decedent, the date of death, and the name of the custodian of the original will. This affidavit is used to prove the validity of the copy of a will in legal proceedings. There are two different types of Illinois Affidavit as To Copy of Will. The first is a Self-Proving Affidavit, which is used when the original will was signed in the presence of two witnesses who are both qualified to witness a will. The second is a Non-Self-Proving Affidavit, which is used when the original will was not signed in the presence of two witnesses.