Certain type of a The reproduction or alteration of a document or security element with the intent to deceive the public. A counterfeit banknote looks authentic and has been manufactured or altered fraudulently. In most countries, currency counterfeiting is a criminal offence under the criminal code. More A banknote (or ‘bill’ as it is often referred to in the US) is a type of negotiable promissory note, issued by a bank or other licensed authority, payable to the bearer on demand. More.