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 Maine, writing a bad check, also known as issuing a non-sufficient funds (NSF) check, can be a criminal offense under certain circumstances. Maine law considers it a crime when a person intentionally writes a check knowing that there are not enough funds in the account, or if the account is closed. This is covered under Title 17-A, §708 of the Maine Criminal Code, which addresses the issue of 'negotiating a worthless instrument.' The law also applies to situations where a person writes a check for more funds than are in the account, deposits it into a second account, and withdraws the funds before the check clears. The severity of the offense can range from a Class E crime for checks of a small amount to a Class B crime for checks involving larger sums. While accidental overdrafts may not lead to criminal charges, Maine law does not require proof of the exact account balance at the time the check was written to establish that a person knowingly issued a bad check. Instead, the focus is on the intent or knowledge of insufficient funds at the time of writing the check. It is important for individuals to manage their accounts responsibly to avoid potential criminal charges related to bad checks.