Taxpayers did not establish a basis to abate an estimated tax penalty, late payment penalty, or interest, despite citing COVID-19-related income fluctuations and payment hardships. The taxpayers advanced only reasonable cause arguments to support their request for the abatement of penalties and interest. However, there was no statutory provision that allowed the estimated tax penalty to be abated based on a finding of reasonable cause. With respect to the late payment penalty, the taxpayers failed to prove reasonable cause for the late payment, as they did not present any evidence that they acted as ordinarily intelligent and prudent business people to ascertain their tax liability prior to the payment due date. Finally, the imposition of interest was mandatory and could be abated only in limited situations, none of which was applicable in this case. Leebow, California Office of Tax Appeals, 2025-OTA-426P, May 7, 2025