UNDER Section 222 of the National Internal Revenue Code (Tax Code), the 10-year prescriptive period for the Commissioner of Internal Revenue (CIR) to assess tax applies in cases where a taxpayer files a false or fraudulent return with intent to evade tax or fails or omits to file a return. This 10-year period is an exception to the general rule prescribed under Section 203 of the Tax Code, which provides that internal revenue taxes shall be assessed within three years from the day the return was actually filed, or the last day for filing the return stated under the Tax Code.

It should be noted that Section 222 speaks of three distinct cases when the extraordinary ten-year assessment period may be invoked by the CIR: (1) filing a false return, (2) filing a fraudulent return, or (3) omitting to file a return.