A person with a bank account writes a bad check (also known as a non-sufficient funds or NSF check) when he deliberately or with knowledge writes a check for an amount of funds he knows are not available in the account. The crime of writing a bad check may also occur when a person writes a check on an account that has been closed. Another bad check scheme that may result in criminal charges occurs when an account holder writes a check for an amount in excess of the funds in the account, and deposits the check in a second account (often at a different bank)—and then withdraws the funds from the second account before the check is presented to the first bank for payment.

Bad check laws vary from state to state, and are usually located in the state’s penal or criminal code (statutes). Banks and criminal prosecutors recognize that a person can inadvertently write a check for more than the funds on deposit in their account, and not every instance will result in criminal charges. But many state laws have an expansive definition of the required knowledge or deliberate intent to write a bad check, and a criminal prosecutor does not have to prove a defendant charged with a bad check offense knew exactly how much money was in the account when the defendant wrote the check to prove the defendant knew he was writing a bad check or deliberately wrote a bad check.

In Washington State, writing a bad check, also known as a check with non-sufficient funds (NSF), can lead to criminal charges under certain circumstances. The crime occurs when a person knowingly writes a check without having sufficient funds in their account, or writes a check on an account that is closed. Additionally, it is considered a crime if someone writes a check for more than the account balance, deposits it into a second account, and withdraws the funds before the check clears. While not every instance of an NSF check will result in criminal charges, as mistakes can happen, Washington law does consider the act of knowingly writing a bad check as a form of fraud. The state's statutes require proof of intent or knowledge that the funds were insufficient at the time the check was written. The specific statutes addressing bad checks can be found in the Revised Code of Washington (RCW), and the severity of the charges can range from a misdemeanor to a felony, depending on the amount of the check and other circumstances.