(a) Five percent shall be added to a tax for each 30-day period or fraction of the period during which the taxpayer fails to file at the time or times required by law or regulation a return or report, or pay the full amount of the tax, or a portion or a deficiency of the tax, as finally determined by the department and required by this title, unless it is shown that the failure is due to a reasonable cause and not to wilful neglect. The penalty may not exceed 25 percent in the aggregate. The penalty is computed only on the unpaid balance of the tax liability as determined by the department. The department shall prescribe by regulation circumstances which constitute reasonable cause for purposes of this section.

(b) If a tax deficiency or part of a tax deficiency is due to negligence or intentional disregard of law or regulation without intent to defraud, five percent of the total amount of the tax deficiency shall be assessed, collected, and paid in the same manner as a tax deficiency.

(c) If a tax deficiency or part of a tax deficiency is due to fraud, a civil fraud penalty equal to 50 percent of the tax due or $500, whichever is greater, shall be added to the tax. This penalty is in addition to penalties determined under (a) or (b) of this section.

(d) A person required to collect or account for a tax imposed by this title who wilfully fails to collect the tax or to truthfully account for and pay over the tax, or wilfully attempts to evade payment of the tax is, in addition to other penalties provided by law, liable for a civil penalty equal to the total amount of the tax not collected, not accounted for, not paid over, or evaded. The penalty imposed by this subsection is in place of the tax not paid to the state. This penalty shall be paid upon demand by the commissioner or a designee of the commissioner, and shall be assessed and collected in the same manner as taxes are assessed and collected under this title.

(e) A penalty imposed by this section shall be collected at the same time, in the same manner, and as a part of the original tax. However, if the original tax is paid before neglect or fraud is discovered, the penalty shall be collected in the same manner as the original tax. Interest may not be collected on a penalty imposed by this section.

(f) Unless the department determines that failure to comply with AS 43.05.045 is due to a reasonable cause, the department shall assess a civil penalty of $25 or one percent of the total tax before any payment, whichever is greater, against a taxpayer who fails to submit electronically a return or report under AS 43.05.045.