The penalty for late filing of Form 1125-E, which is the Compensation of Officers, is determined by the Internal Revenue Service (IRS). As of 2021, the penalty can be the greater of $215 or 1.5% of the unpaid tax per month or part of a month that the return is late, up to a maximum penalty of 25% of the unpaid tax amount. Additionally, if the IRS determines that the late filing is due to intentional disregard, the penalty may increase to 5% per month, up to a maximum of 25%. It's important to note that these penalties are subject to change, so it's recommended to consult the current IRS guidelines or seek professional advice.