- A notary public (a.k.a. notary or public notary; notaries public) of the common law is a public officer constituted by law to serve the public in non-contentious matters usually concerned with general financial transactions, estates, deeds, powers-of-attorney, and foreign and international business. A notary's main functions are to validate the signature of a person (for purposes of signing a document); administer oaths and affirmations; take affidavits and statutory declarations, including from witnesses; authenticate the execution of certain classes of documents; take acknowledgments (e.g., of deeds and other conveyances); protest notes and bills of exchange; provide notice of foreign drafts; prepare marine or ship's protests in cases of damage; provide exemplifications and notarial copies; and, to perform certain other official acts depending on the jurisdiction. Such transactions are known as notarial acts, or more commonly, notarizations. The term notary public only refers to common-law notaries and should not be confused with civil-law notaries.
- With the exceptions of Louisiana, Puerto Rico, Quebec (whose private law is based on civil law), and British Columbia (whose notarial tradition stems from scrivener notary practice), a notary public in the rest of the United States and most of Canada has powers that are far more limited than those of civil-law or other common-law notaries, both of whom are qualified lawyers admitted to the bar: such notaries may be referred to as notaries-at-law or lawyer notaries. Therefore, at common law, notarial service is distinctly different from the practice of law, and giving legal advice and preparing legal instruments is forbidden to lay notaries such as those appointed throughout most of the United States. Despite these distinctions, lawyers in the United States may apply to become notaries, and this class of notary is allowed to provide legal advice, such as determining the type of act required (affidavit, acknowledgment, etc.).
- Notaries are appointed by a government authority, such as a court, governor or lieutenant governor, or by a regulating body often known as a society or faculty of notaries public. For lawyer notaries, an appointment may be for life, while lay notaries are usually commissioned for a briefer term (often 3 to 5 years in the U.S.), with the possibility of renewal.
- In most common law countries, appointments and their number for a given notarial district are highly regulated. However, since the majority of American notaries are lay persons who provide officially required services, commission numbers are not regulated, which is part of the reason why there are far more notaries in the United States than in other countries (4.5 million vs. approx. 740 in England and Wales and approx. 1,250 in Australia and New Zealand). Furthermore, all U.S. and some Canadian notarial functions are applied to domestic affairs and documents, where fully systematized attestations of signatures and acknowledgment of deeds are a universal requirement for document authentication. In the U.S., notaries public do not authenticate documents in a traditional sense: instead, they authenticate that the signature(s) on a document belongs to the person(s) claiming to be the signer(s), thus ensuring trust among interested parties. By contrast, outside North American common law jurisdictions, notarial practice is restricted to international legal matters or where a foreign jurisdiction is involved, and almost all notaries are also qualified lawyers.
- For the purposes of authentication, most countries require commercial or personal documents which originate from or are signed in another country to be notarized before they can be used or officially recorded or before they can have any legal effect. To these documents a notary affixes a notarial certificate–a separate document stating the notarial act performed and upon which the party(ies) and notary sign–which attests to the execution of the document, usually by the person who appears before the notary, known as an appearer or constituent (U.S.). In the U.S., many documents include the notarial wording within the document, thus eliminating the need for an additional page for the certificate only (i.e., the document is signed and notarized, including application of the Notary’s seal). In cases where notaries are also lawyers, such a notary may also draft legal instruments known as notarial acts or deeds which have probative value and executory force, as they do in civil law jurisdictions. Originals or secondary originals are then filed and stored in the notary's archives, or protocol. As noted, lay notaries public in the U.S. are forbidden to advise signers as to which type of act suits the signer’s situation: instead, the signer must provide the certificate/wording that is appropriate.
- Notaries are generally required to undergo special training in the performance of their duties, often culminating in an examination and ongoing education/re-examination upon commission renewal. Some must also first serve as an apprentice before being commissioned or licensed to practice their profession. In some countries, even licensed lawyers, e.g., barristers or solicitors, must follow a prescribed specialized course of study and be mentored for two years before being allowed to practice as a notary (e.g., British Columbia, England). However, notaries public in the U.S., of which the vast majority are lay people, require only a brief training seminar and are expressly forbidden to engage in any activities that could be construed as the unlicensed practice of law unless they are also qualified attorneys. That said, even lay notaries public must know all applicable laws in their jurisdiction (e.g., state) to practice, and a commission could be revoked for a single deviation from such laws. Notarial practice is universally considered to be distinct and separate from that of an attorney (solicitor/barrister). In England and Wales, there is a course of study for notaries which is conducted under the auspices of the University of Cambridge and the Society of Notaries of England and Wales. In the State of Victoria, Australia, applicants for appointment must first complete a Graduate Diploma of Notarial Practice which is administered by the Sir Zelman Cowen Centre in Victoria University, Melbourne. The United States is a notable exception to these practices: lawyer-notaries need only be approved by their jurisdiction and possibly by a local court or bar association.
- In bi-juridical jurisdictions, such as South Africa or Louisiana, the office of notary public is a legal profession with educational requirements similar to those for attorneys. Many even have institutes of higher learning that offer degrees in notarial law. Therefore, despite their name, "notaries public" in these jurisdictions are in effect civil law notaries.