XXI. MMM, Inc., a domestic telecommunications company, handles incoming telecommunications services for non-resident foreign companies by relaying international calls within the Philippines. To broaden the coverage of its telecommunications services throughout the country, MMM, Inc. entered into various interconnection agreements with local carriers. The non-resident foreign corporations pay MMM, Inc. in US dollars inwardly remitted through Philippine banks, in accordance with the rules and regulations of the Bangko Sentral ng Pilipinas. MMM, Inc. filed its Quarterly VAT Returns for 2000. Subsequently, MMM, Inc. timely filed with the BIR an administrative claim for the refund of the amount of P6,321,486.50, representing excess input VAT attributable to its effectively zero-rated sales in 2000. The BIR ruled to deny the claim for refund of MMM, Inc. because the VAT official receipts submitted by MMM, Inc. to substantiate said claim did not bear the words "zero-rated" as required under Section 4.108-1 of Revenue Regulations (RR) No. 7-95. On appeal, the CTA division and the CT A en bane affirmed the BIR ruling. MMM, Inc. appealed to the Supreme Court arguing that the NIRC itself did not provide for such a requirement. RR No. 7-95 should not prevail over a taxpayer's substantive right to claim tax refund or credit. a. Rule on the appeal of MMM, Inc. (3%) b. Will your answer in (a) be any different if MMM, Inc. was claiming refund of excess input VAT attributable to its effectively zero-rated sales in 2012? (2%)