In the Philippine tax landscape, the National Internal Revenue Code (NIRC) provides the skeleton of tax law, but Revenue Memorandum Circulars (RMCs) issued by the Bureau of Internal Revenue (BIR) provide the flesh—the specific interpretations, clarifications, and administrative updates that dictate day-to-day compliance.

Understanding these guidelines is critical for both individual and corporate taxpayers to avoid the heavy hand of surcharges, interest, and compromise penalties.

The Role of Revenue Memorandum Circulars (RMCs)

While Statutes (Laws) and Revenue Regulations (RRs) establish legal frameworks, RMCs are administrative issuances that clarify specific issues or announce temporary changes. They are often used to:

Extend filing deadlines during calamities or system downtimes.
Clarify the application of new tax rates (e.g., under the CREATE or EASE laws).
Provide step-by-step instructions for electronic filing systems (eForms vs. eFPS).

Core Filing Deadlines and Requirements

Tax deadlines in the Philippines generally follow a predictable cycle, though RMCs frequently adjust these dates if they fall on weekends or holidays.

1. Income Tax Returns (ITR)

Annual ITR: For individuals and corporations (calendar year), the hard deadline is April 15 of the following year.
Quarterly ITR: * Individuals: 15th of May (Q1), August (Q2), and November (Q3).
Corporations: 60 days following the close of each of the first three quarters.

2. Value-Added Tax (VAT) and Percentage Tax

Monthly/Quarterly: Under the Ease of Paying Taxes (EOPT) Act, significant shifts have occurred to streamline these filings. Traditionally, VAT was filed monthly and quarterly; however, recent circulars have moved toward emphasizing quarterly filings to reduce administrative burdens.
Deadline: Generally on or before the 25th day following the close of the taxable quarter.

3. Withholding Taxes

Compensation/Expanded: Filed via Form 1601-C or 1601-E.
Deadline: Usually the 10th day of the following month (for manual filers) or according to the staggered schedule for eFPS filers.

Modern Filing Channels: eFPS vs. eBIRForms

The BIR distinguishes between taxpayers based on their required filing method, often clarified through RMCs to manage server traffic.

Electronic Filing and Payment System (eFPS): Reserved primarily for Large Taxpayers, TAMP (Taxpayer Account Management Program) companies, and government bidders. It is a web-based system for paperless filing and e-payment.
eBIRForms: A standalone application for non-eFPS taxpayers (including Small and Medium Enterprises and Individuals). Taxpayers download the package, fill it out offline, and submit it online.
Manual Filing: Now strictly limited to specific circumstances (e.g., system downtime or specific taxpayer categories) as mandated by recent "Ease of Paying Taxes" circulars.

Key Compliance Guidelines under Recent RMCs

The "Ease of Paying Taxes" (EOPT) Impact

Recent RMCs have integrated the EOPT Act (Republic Act No. 11976), which introduced:

File-and-Pay Anywhere: Taxpayers can now file and pay their internal revenue taxes at any Authorized Agent Bank (AAB) or Revenue District Office (RDO), regardless of where they are registered.
Classification of Taxpayers: Taxpayers are now categorized as Micro, Small, Medium, or Large, with simplified requirements for the smaller categories.
Removal of Annual Registration Fee: RMCs have confirmed that taxpayers no longer need to pay the PHP 500 annual registration fee (ARF).

Substantiation Requirements

RMCs frequently clarify that for an expense to be deductible, it must be supported by an Invoice (for both goods and services under EOPT). The previous distinction between "Sales Invoices" and "Official Receipts" has been unified to simplify the audit trail.

Consequences of Non-Compliance

Failure to adhere to the deadlines and guidelines set forth in RMCs triggers Section 248 and 249 of the Tax Code:

Surcharge: 25% for simple late filing; 50% for willful neglect or fraudulent returns.
Interest: Double the legal interest rate set by the Bangko Sentral ng Pilipinas (currently 12% per annum on the unpaid amount).
Compromise Penalty: A graduated schedule based on the amount of tax unpaid, intended to avoid criminal prosecution.