On March 10, 2015, the Department denied the Taxpayer’s request for refund of an amount that was offset from her 2013 New Mexico personal income tax refund. The offset was done to satisfy a penalty for underpayment of estimated tax on her 2011 and 2012 personal income tax. On March 23, 2015, the Taxpayer filed a protest of the denial. At some point, the Department refunded the amount taken for the 2012 tax year because a formal assessment had not been done. On May 22, 2015, the Department formally assessed the Taxpayer for the penalty for underpayment of estimated tax for the 2012 tax year. On June 4, 2015, the Taxpayer filed a protest of the assessment. In 2011 and 2012, the Taxpayer was required to make estimated payments for personal income tax. The Taxpayer made some estimated payments, but not enough to satisfy the requirement under Section 7-2-12.2 NMSA 1978, which requires the payments to equal 90% of the current taxable year, or 100% of the prior tax year, whichever is less. The estimated payments are to be equal payments made by the 15th days of April, June and September of the taxable year, and by the 15th day of January of the following year. When a Taxpayer makes underpayments of the estimated tax, a penalty applies to the amounts of underpayment for the period of underpayment. The Taxpayer argued that the statute was unfair and unreasonable. The law is clear and the Taxpayer was required to make the estimated payments. Penalty applies when any installment of estimated tax is underpaid. The Taxpayer failed to pay the full amounts of estimated tax due when it was due, so penalty was properly assessed. The Taxpayer’s protest was denied.