A taxpayer's failure to appeal to the Secretary of Justice within 30 days from
the effectivity of a revenue ordinance bars the subsequent protest and/or claim
for refund on the ground of its invalidity. Such failure is fatal to the
taxpayer's claim, even if other taxpayers have questioned the same ordinance
with the Secretary of Justice. As long as the revenue ordinance has not been
declared to be invalid with finality, the taxpayer who did not earlier question
the same before the Secretary of Justice may not assail it in a subsequent
protest and/or claim for refund. (Jardine Davies Insurance Brokers, Inc. v.
Aliposa, G.R. No. 118900, February 27, 2003)
