Section 205.23 - Determination of tax liability; notice; payment of deficiency; interest and penalties(1) If the department believes, based upon either the examination of a tax return, a payment, or an audit authorized by this act, that a taxpayer has not satisfied a tax liability or that a claim was excessive, the department shall determine the tax liability and notify the taxpayer of that determination. A liability for a tax administered under this act is subject to the interest and penalties prescribed in subsections (2) to (5).(2) If the amount of a tax paid is less than the amount that should have been paid or an excessive claim has been made, the deficiency and interest on the deficiency at the current monthly interest rate of 1 percentage point above the adjusted prime rate per annum from the time the tax was due, and until paid, are due and payable after notice and informal conference as provided in this act. A deficiency in an estimated payment as may be required by a tax statute administered under this act shall be treated in the same manner as a tax due and shall be subject to the same current monthly interest rate of 1 percentage point above the adjusted prime rate per annum from the time the payment was due, until paid. As used in this section, "adjusted prime rate" means the average predominant prime rate quoted by not less than 3 commercial banks to large businesses, as determined by the department of treasury. The adjusted prime rate is to be based on the average prime rate charged by not less than 3 commercial banks during the 6-month period ending on March 31 and the 6-month period ending on September 30. One percentage point shall be added to the adjusted prime rate, and the resulting sum shall be divided by 12 to establish the current monthly interest rate. The resulting current monthly interest rate based on the 6-month period ending March 31 becomes effective on the following July 1, and the resulting current monthly interest rate based on the 6-month period ending September 30 becomes effective on January 1 of the following year.(3) Except as provided in subsection (4), if any part of the deficiency or an excessive claim for credit is due to negligence, but without intent to defraud, a penalty of $10.00 or 10% of the total amount of the deficiency in the tax, whichever is greater, plus interest as provided in subsection (2), shall be added. The penalty becomes due and payable after notice and informal conference as provided in this act. If a taxpayer subject to a penalty under this subsection demonstrates to the satisfaction of the department that the deficiency or excess claim for credit was due to reasonable cause, the department shall waive the penalty. The penalty prescribed by this subsection shall not be imposed after June 30, 1994 unless and until the department submits for public hearing pursuant to the administrative procedures act of 1969, Act No. 306 of the Public Acts of 1969, being sections 24.201 to 24.328 of the Michigan Compiled Laws, a rule defining what constitutes reasonable cause for waiver of the penalty under this subsection, which definition shall include illustrative examples.(4) If any part of the deficiency or an excessive claim for credit is due to intentional disregard of the law or of the rules promulgated by the department, but without intent to defraud, a penalty of $25.00 or 25% of the total amount of the deficiency in the tax, whichever is greater, plus interest as provided in subsection (2), shall be added. The penalty becomes due and payable after notice and informal conference as provided in this act. If a penalty is imposed under this subsection and the taxpayer subject to the penalty successfully disputes the penalty, the department shall not impose a penalty prescribed by subsection (3) to the tax otherwise due.(5) If any part of the deficiency or an excessive claim for credit is due to fraudulent intent to evade a tax, or to obtain a refund for a fraudulent claim, a penalty of 100% of the deficiency, plus interest as provided in subsection (2), shall be added. The penalty becomes due and payable after notice and informal conference as provided in this act.Add. 1980, Act 162, Eff. 9/17/1980 ;--Am. 1986, Act 58, Eff. 5/1/1986 ;--Am. 1991, Act 83, Imd. Eff. 7/18/1991 ;--Am. 1993, Act 14, Imd. Eff. 4/1/1993.