The New York notary certificate of subscribing witness is a document with which a notary public verifies the identity of an individual who has acted as a witness for the signing of a legal instrument. A “subscribing witness” is required by living trusts and other property transfers, and they must personally know the principal signer, witness the signing of the document, and sign as witness. This witness will have to present the signed document to a notary public and identify themselves with photo ID (if the notary public doesn’t personally know them). Furthermore, subscribing witnesses are required to supply their full address. Once the notary public has verified the witness’ identity and viewed their signature, they can fill out the notary certificate to notarize the witness’ signature.