e. Submission of Supporting Documents by Taxpayer

Assessment Due Process Under Section 228 and CTA Jurisdiction

Taxpayers must be accorded administrative due process, which requires the issuance of a valid assessment under Section 228 of the Tax Code¹. As held in CIR v. Elric Auxiliary Services Corporation/Sacred Heart Gas Station, G.R. No. 226945, 19 February 2026, the Commissioner of Internal Revenue cannot bypass the statutory assessment requirements under Section 228 to surreptitiously collect deficiency taxes through Section 115 notices¹.

The authority to examine or assess is a matter governed by the Tax Code and falls within the exclusive appellate jurisdiction of the Court of Tax Appeals under the "other matters" clause of Section 7(a)(1)¹. Under CIR v. Elric Auxiliary Services Corporation/Sacred Heart Gas Station, adherence to the mandatory assessment procedures under Section 228 ensures that taxpayers are given full opportunity to exercise their rights and receive due process in tax disputes¹.