Taxpayer protested the imposition of penalty and interest on his receipts from performing consulting services in New Mexico. The Taxpayer had moved to New Mexico and was not aware that his receipts were subject to gross receipts tax. Taxpayers are under a duty to ascertain the possible tax consequences of their actions and failure to do so amounts to negligence for purposes of the imposition of penalty. The fact that the Taxpayer consulted with H&R Block to prepare his income tax returns and H&R Block failed to advise him about the gross receipts tax does not negate the Taxpayer’s negligence in the absence of proof that he received any advice with respect to gross receipts tax. The imposition of interest was also upheld because interest is imposed any time a tax is not paid when it is due, regardless of the reason the tax was not paid. Finally, the Department’s delay in assessing the Taxpayer does not excuse the imposition of interest so long as the assessment is issued within the statute of limitations for assessing tax. Protest denied.