Forgery is the crime of creating a false document, altering a document, or writing a false signature for the illegal benefit of the person making the forgery. This includes improperly filling in a blank document, like an automobile purchase contract, over a buyer's signature, with the terms different from those agreed.

Forgery may be classified as a misdemeanor or felony. This type of classification system is termed as being a “wobbler." A wobbler is punishable by either imprisonment in the state prison or by imprisonment in the county jail for up to one year. It is up to the prosecutor to charge the forgery case as a misdemeanor or felony. If convicted, the judge may sentence the crime as either a misdemeanor or felony.

California Penal Code Section 470 states that any person who has intent to defraud and signs another person’s name, without consent, is guilty of forgery. Every person who, with the intent to defraud, counterfeits or forges the seal or handwriting of another is guilty of forgery. Further, every person who, with the intent to defraud, alters, corrupts, or falsifies any record of any will, codicil, conveyance, or other instrument, the record of which is by law evidence, or any record of any judgment of a court or the return of any officer to any process of any court, is guilty of forgery. The following forged items apply:

?Any check, bond, bank bill, or note
?Cashier's check, traveler's check, money order, post note, draft
?Any controller's warrant for the payment of money at the treasury, county order or warrant, or request for the payment of money, receipt for money or goods, bill of exchange, promissory note, order, or any assignment of any bond, writing obligatory, or other contract for money or other property, contract, due bill for payment of money or property, receipt for money or property, passage ticket, lottery ticket or share purporting to be issued under the California State Lottery Act of 1984
?Trading stamp
?Power of attorney
?Certificate of ownership or other document evidencing ownership of a vehicle or undocumented vessel
?Any certificate of any share, right, or interest in the stock of any corporation or association
?The delivery of goods or chattels of any kind, or for the delivery of any instrument of writing
?Acquittal, release or discharge of any debt, account, suit, action, demand, or any other thing, real or personal
?Any transfer or assurance of money, certificate of shares of stock, goods, chattels, or other property whatever
?Any letter of attorney, or other power to receive money, or to receive or transfer certificates of shares of stock or annuities
?Let, lease, dispose of, alien, or convey any goods, chattels, lands, or tenements, or other estate, real or personal