A notary or notary public is a person commissioned by a state and authorized to administer oaths, take acknowledgments and depositions, attest and certify documents and protest negotiable instruments for nonpayment or nonacceptance.

The eligibility, appointment, tenure, powers and compensation of notaries public are determined and defined by statute in the various jurisdictions. The power to take acknowledgments is a statutory power and must strictly follow the statutory requirements.

Notaries public are usually appointed to act within a certain county or political division, which is the limit of their jurisdiction. They are not authorized to act elsewhere and any acknowledgment taken beyond their territorial limit is void.

One who is a party to an instrument, no matter how small or nominal therein, cannot act as a notary public with reference thereto. However, a mere relationship to a party does not disqualify a notary.

In most states, a notary public must have an official seal. The purpose of the seal is to authenticate the authority of the notary to which the notarial certificate is duly affixed. Provisions are sometimes established by law as to the form of the seal and its inscriptions. In general, when embossed, stamped, imprinted, or affixed to an instrument the seal must clearly show:

• The name of the notary.
• The words: "notary public."
• The name of the state.
• The name of the county in which the notary is commissioned (in some states).
• The date of the expiration of the notary's commission.
• The state seal (in some states).

In some jurisdictions, notaries public are required to keep a record or journal book and to enter therein their notarial acts.