A final assessment notice was issued by the BIR on June 13, 2000 and received by the taxpayer on June 15, 2000. The taxpayer protested the assessment on July 31, 2000. The protest was initially given due course but was eventually denied by the Commissioner of Internal Revenue in a decision dated June 15, 2005. The taxpayer then filed a petition for review with the Court of Tax Appeals (CTA), but the CTA dismissed the same.

Assume that the CTA’s decision dismissing the petition for review has become final. May the Commissioner legally enforce collection of the delinquent tax? Explain. (2009 BAR)