New Jersey Proof of Witness of Codicil is a legal document required by the state of New Jersey that must be provided to the court in order to prove that the witnesses to a codicil (amendment to a will) are competent to attest to the document. This document must include the name of each witness, the date of the codicil, and the signature of each witness. There are two types of New Jersey Proof of Witness of Codicil: an affidavit form and a certification form. The affidavit form requires a witness to swear in front of a notary public that the facts stated in the document are true to the best of their knowledge. The certification form requires the witness to sign the document and provide an attestation that the facts stated are true. Both forms must be signed by two witnesses in order for the document to be accepted by the court.