§ 6657. Bad checks
If any instrument in payment, by any commercially acceptable means, of any amount receivable under this title is not duly paid, in addition to any other penalties provided by law, there shall be paid as a penalty by the person who tendered such instrument, upon notice and demand by the Secretary, in the same manner as tax, an amount equal to 2 percent of the amount of such instrument, except that if the amount of such instrument is less than $1,250, the penalty under this section shall be $25 or the amount of such instrument, whichever is the lesser. This section shall not apply if the person tendered such instrument in good faith and with reasonable cause to believe that it would be duly paid.