View a list of the available Notary Public forms available from the California Secretary of State's office here. Signing the affidavit.It is essential to sign the document only in the presence of a notary public. 7. When notarizing an affidavit, make sure the signer appears before you in person. State of California. This article and video will show Notaries to fill out each part of a notarial certificate, and common mistakes to avoid. The affiant must sign the affidavit in the presence of a notary public or another authorized official. Ensure that the signature is dated. A notary public or other officer completing this certificate verifies only the identity of the individual who signed the document. A notary public or other officer completing this certificate verifies only the identity of the individual who signed the document.