This article and video will show Notaries to fill out each part of a notarial certificate, and common mistakes to avoid. A PA Notary Public serves as an impartial witness to the signing of important documents, ensuring the identity of signers.The applicant should record the commission, executed bond and oath form in the Recorder of Deeds in the county where their office is located. Do I fill the Affidavit of Identity out before going to a notary? No. A notary expects to witness your signature. If a notary public discovers an error in a notarial act after completing the act, then the notary public should notarize the signature on the document again.