SC: No valid assessment-period waiver if tax kind, amount NOT shown

In Commissioner of Internal Revenue (CIR) v. Systems Technology Institute, Inc. (G.R. No. 220835, July 26, 2017), the Supreme Court ruled that waivers extending the prescriptive period of tax assessments must be compliant with RMO No. 20-90 and must indicate the nature and amount of the tax due, to wit:
These requirements are mandatory and must strictly be followedTo be sure, in a number of cases, this Court did not hesitate to strike down waivers which failed to strictly comply with the provisions of RMO 20-90 and RDAO 05-01.

x x x x

The Court also invalidated the waivers executed by the taxpayer in the case of Commissioner of Internal Revenue v. Standard Chartered Bank, because: (1) they were signed by Assistant Commissioner-Large Taxpayers Service and not by the CIR; (2) the date of acceptance was not shown; (3) they did not specify the kind and amount of the tax due; and (4) the waivers speak of a request for extension of time within which to present additional documents and not for reinvestigation and/or reconsideration of the pending internal revenue case as required under RMO No. 20-90.

Tested against the requirements of RMO 20-90 and relevant jurisprudence, the Court cannot but agree with the CTA's finding that the waivers subject of this case suffer from the following defects:

x x x x
3. Similar to Standard Chartered Bank, the waivers in this case did not specify the kind of tax and the amount of tax due. It is established that a waiver of the statute of limitations is a bilateral agreement between the taxpayer and the BIR to extend the period to assess or collect deficiency taxes on a certain date. Logically, there can be no agreement if the kind and amount of the taxes to be assessed or collected were not indicatedHence, specific information in the waiver is necessary for its validity. (Emphasis supplied)
In CIR v. La Flor Dela Isabela (G.R. No. 211289, January 14, 2019), the September 3, 2008, February 16, 2009 and December 2, 2009 Waivers failed to indicate the specific tax involved and the exact amount of the tax to be assessed or collected. As above-mentioned, these details are material as there can be no true and valid agreement between the taxpayer and the CIR absent these information. Clearly, the Waivers did not effectively extend the prescriptive period under Section 203 on account of their invalidity. The assessments had already prescribed as there was no valid waiver.