The subscribing-witness certificate is typically used when a Principal Signer who cannot appear before the Notary directs a third party (the Subscribing Witness) to witness that Principal’s Signing or acknowledging of a document and then to bring the signed document to the Notary Public to vouch for its execution.
This Subscribing Witness signs (subscribes) on the same document and takes an Oath or Affirmation, pledging truthfulness, from the Notary Public. The witness should be personally known by the Notary Public, or identified by a Credible Witness whom the Notary Public personally knows.
In most states, a Proof of Execution by a Subscribing Witness is a legally acceptable substitute for an Acknowledgment by the Principal Signer. It is never an acceptable substitute for a Jurat, however, which requires the Principal Signer to sign and take an oath in the Notary Public’s presence.
A Subscribing-Witness Certificate is often referred to as a “WitnessJurat,” because the Subscribing Witness must be put under oath and sign the document. A Subscribing Witness is sometimes known as an “Executing Witness.”