The Philippine Commission enacted Act No. 1189, creating the first comprehensive internal revenue law in the Philippines. This foundational statute established the Bureau of Internal Revenue and imposed taxes on income, business, documents, and commodities.

The Philippine Legislature substantially revised the internal revenue law to expand tax coverage and increase rates. This act consolidated various revenue measures and introduced new administrative provisions for better enforcement.

The Commonwealth Congress enacted the first codified National Internal Revenue Code, systematically organizing all internal revenue laws into a single statute. This represented a complete recodification rather than mere amendment.

President Marcos issued Presidential Decree No. 1158, completely revising the National Internal Revenue Code to modernize tax laws and increase government revenues. This became the foundation of the modern Philippine tax system.

President Aquino issued EO 273 introducing a 10% value-added tax to replace the manufacturer's sales tax. This fundamental reform shifted the Philippines to a consumption-based tax system.

President Ramos signed into law the Tax Reform Act of 1997, completely revising the National Internal Revenue Code. This landmark legislation modernized tax administration, simplified procedures, and adjusted rates to contemporary economic conditions.

The Supreme Court held that capitalized interest during project construction is not deductible as interest expense but must be treated as capital expenditure. This ruling clarified the proper tax treatment of interest incurred for capital projects.

President Arroyo signed the Expanded VAT Law increasing the VAT rate to 12% and broadening coverage to include previously exempt services. This controversial reform aimed to address persistent budget deficits.

The Supreme Court ruled that zero-rated VAT sales are distinct from exempt sales, and that taxpayers are entitled to refund or tax credit of input VAT on zero-rated sales even without prior application for zero-rating.

The Supreme Court held that excess input VAT may be carried over to succeeding quarters but once the option to carry over is made, it becomes irrevocable for that taxable period. Refund and carry-over cannot both be claimed.

This law restructured the motor vehicle user's charge under the NIRC, adjusting rates based on vehicle type and engine displacement. The reform aimed to rationalize automotive taxation and generate additional infrastructure revenues.

President Duterte signed the TRAIN Law as the first package of comprehensive tax reform, reducing personal income taxes while increasing excise taxes on petroleum, automobiles, and sugar-sweetened beverages. This major reform took effect January 1, 2018.

The Supreme Court En Banc ruled on the prescriptive period for VAT refund claims, holding that the 120+30 day period is mandatory but premature filing is allowed during a specific window when BIR ruled otherwise.

The Corporate Recovery and Tax Incentives for Enterprises (CREATE) Act reduced corporate income tax rates to 25% for large corporations and 20% for MSMEs, while rationalizing fiscal incentives. This reform aimed to enhance competitiveness amid pandemic recovery.

The Ease of Paying Taxes Act simplified tax compliance procedures, reduced documentary requirements, and mandated digital systems for filing and payment. This reform aimed to improve the Philippines' ease of doing business rankings.