§ 7-1-60 NMSA 1978

In any proceeding pursuant to the provisions of the Tax Administration Act, the department shall be estopped from obtaining or withholding the relief requested if it is shown by the party adverse to the department that the party's action or inaction complained of was in accordance with any regulation effective during the time the asserted liability for tax arose or in accordance with any ruling addressed to the party personally and in writing by the secretary, unless the ruling had been rendered invalid or had been superseded by regulation or by another ruling similarly addressed at the time the asserted liability for tax arose.