Forgery is the criminal offense of making or uttering a false document or other instrument with the intent to defraud or harm someone—including a written or printed document, money, coins, tokens, stamps, checks, cashier’s checks, bonds, money orders, traveler’s checks, real property deeds, contracts, stock certificates, lottery tickets, wills, seals, credit cards, badges, trademarks, and symbols of value, right, privilege, or identification. Uttering a document means to declare—either directly or indirectly, and through words or actions—that the document is legitimate and what it purports to be.

Forging a document includes altering, making, completing, executing, or authenticating a writing so it purports (1) to be the act of another who did not authorize that act; (2) to have been executed at a time or place or in a numbered sequence other than was in fact the case; or (3) to be a copy of an original when no such original existed.

Forging a document also includes the acts of issuing, transferring, registering the transfer of, recording, passing, publishing, or otherwise uttering a document that is forged. And in some states the mere possession of a forged document with the intent to utter it constitutes forging a document.

The definitions, penalties, and punishments for the crime of forgery vary from state to state and are generally located in a state’s statutes—often in the penal or criminal code.

In New York, forgery is defined under Penal Law Article 170. It is considered a crime involving the creation, alteration, or use of a forged instrument with the intent to defraud, deceive, or injure another party. The term 'forged instrument' is broadly defined and includes any written instrument that has been falsely made, completed, or altered. The severity of the offense ranges from a misdemeanor to a felony, depending on the type of document involved and the circumstances of the crime. For example, Forgery in the Third Degree (NY Penal Law § 170.05) is a class A misdemeanor and involves any forged instrument. Forgery in the Second Degree (NY Penal Law § 170.10) is a class D felony and includes the forgery of certain types of documents such as deeds, wills, contracts, public records, or prescriptions. The most serious offense, Forgery in the First Degree (NY Penal Law § 170.15), is a class C felony and involves the forgery of currency, securities, or other instruments issued by the government. Additionally, the crime of 'uttering' a forged instrument, which means presenting or using it as if it were genuine, is also illegal and carries similar penalties. Possession of a forged instrument with the intent to use it can also constitute a criminal offense in New York.