Updated for general guidance as of recent Philippine tax rules. This is an explanatory article, not legal advice.

1) The “next business day” rule: the core principle

When a statutory or regulatory tax deadline falls on a Saturday, Sunday, or a legal holiday, the act required (filing and/or payment) may be done on the next working day without incurring late‐payment penalties. This rule, long recognized in Philippine administrative practice and mirrored in the Rules of Court on computation of time, is applied by the Bureau of Internal Revenue (BIR) to due dates for Capital Gains Tax (CGT) and Documentary Stamp Tax (DST), including one-time transactions (ONETT).

Practical takeaways

If your due date is Saturday, you may file and pay Monday (or Tuesday if Monday is a holiday).
This applies whether you submit via eBIRForms/eFPS or over the counter at Authorized Agent Banks/Revenue Collection Officers—provided the filing/payment is completed on the next working day.

2) What taxes are we talking about?

A. Capital Gains Tax (CGT)

On sale or exchange of real property classified as capital asset
- Who: Individuals and corporations selling real property classified as capital asset (not used in business/ordinary course).
- Rate: 6% of the higher of (i) gross selling price or (ii) fair market value (FMV)/zonal value.
- Return/Form: BIR Form 1706 (Capital Gains Tax Return for Onerous Transfer of Real Property).
On sale or exchange of shares of stock not traded on the local stock exchange
- Who: Individuals and corporations selling unlisted (or otherwise not LSE-traded) shares.
- Rate: 15% of net capital gains (TRAIN era).
- Return/Form: BIR Form 1707-A (prevailing form for the 15% regime). Some taxpayers may still encounter BIR Form 1707 in legacy contexts—follow current BIR form instructions.

B. Documentary Stamp Tax (DST)

DST applies to taxable documents (e.g., Deeds of Absolute Sale of real property; stock certificates/transfer documents for share transfers).
Real property conveyances: DST is effectively 1.5% (₱15 for every ₱1,000) of consideration or FMV—whichever is higher.
Share transfers: DST is computed based on a statutory schedule tied to par value/issue/transfer; consult the current DST table for the exact rate applicable to your share document.
Return/Form:
- BIR Form 2000-OT (Documentary Stamp Tax on One-Time Transactions) for ONETT items like a deed of sale.
- BIR Form 2000 (monthly DST) applies to regular, recurring transactions by banks/insurers/etc.

3) Standard deadlines that move when the last day is a weekend/holiday

A. CGT on real property (Form 1706)

Due date: Within 30 days following the date of sale/transfer (often the date of notarization of the deed).
Weekend rule: If the 30th day is a Saturday/Sunday/holiday, the due date shifts to the next working day.

B. CGT on unlisted shares (Form 1707-A)

Common rule: Within 30 days from the date of each transaction (unless a form-specific instruction provides consolidation timing—always read the current form instructions).
Weekend rule: Same next-business-day shift.

C. DST on ONETT (Form 2000-OT)

Due date: On or before the 5th day following the close of the month when the taxable document was made/signed/issued.
- Example: A deed dated July 15 → month closes July 31 → DST due on or before August 5.
Weekend rule: If the 5th is a Saturday/Sunday/holiday, due date shifts to the next working day.

Note: CGT (30-day rule) and DST (5th day after month-end) usually do not fall on the same date. Track both calendars.

4) Illustrative scenarios

Scenario 1: Real property sale (CGT & DST)

Deed notarized: Friday, March 7
CGT (30 days): Sunday, April 6 → moved to Monday, April 7
DST (5th after month-end): Month closes March 31 → due April 5 (Saturday) → moved to Monday, April 7
Result: Both CGT and DST are timely if filed/paid April 7.

Scenario 2: Share sale (unlisted)

Stock sale: Saturday, May 10
CGT (30 days): Monday, June 9 (because the 30th day would have fallen on Sunday)
If your documentary transfer is executed May 12 (Monday), the DST falls into May month-end; due June 5. If June 5 is a holiday, payment June 6 is timely.

5) Filing mechanics and “weekend” nuances

A. eBIRForms/eFPS vs. over-the-counter

If the statutory due date is a weekend/holiday, the system ordinarily accepts returns and treats next-business-day filings/payments as on time.
If you file on the weekend and your authorized bank/payment channel processes value-dating to the next business day, the BIR generally respects the system timestamp/value date shown on the official payment confirmation.

B. Authorized Agent Banks (AABs) and RCOs

If your RDO’s AAB counters are closed on the due date (weekend/holiday), payment on the next working day at AABs/Revenue Collection Officers is considered timely.

C. Systems downtime/force majeure

The BIR periodically issues advisories extending deadlines during widespread system outages or calamities. If an outage coincides with your due date/weekend window, keep proof of downtime (screenshots, advisories) and file/pay immediately upon service restoration or by the announced extended date, whichever applies.

6) What “on time” means (and why it matters)

Paying and filing on or before the next business day when the deadline falls on a non-working day avoids:

25% surcharge (for failure to file/pay on time; 50% only for fraud/willful neglect).
Interest at a rate equal to double the legal interest rate per annum (currently widely understood as 12% p.a. absent a change in the underlying legal rate), computed from the original due date until full payment.
Compromise penalties under BIR schedules.

7) Coordination with CAR (for property/share transfers)

For ONETT transactions that require a Certificate Authorizing Registration (CAR/eCAR) (e.g., real property conveyances; transfers of shares in domestic corporations recorded in the corporate books), the BIR will only process and release the CAR after:

Proper filing of returns (CGT and/or DST),
Full payment of the taxes, and
Submission of documentary requirements (e.g., notarized deed, TINs of parties, IDs, tax clearances if applicable, valuation documents, proof of payment, corporate secretary’s certificates for share transfers, etc.).

A weekend-moved due date does not delay CAR processing if you file and pay on the next business day as allowed.

8) Checklist: if your due date lands on a weekend/holiday

Confirm each tax and its distinct due date
- CGT (real property): 30 days from sale/notarization.
- CGT (unlisted shares): 30 days from transaction (unless the form’s current instructions prescribe consolidation).
- DST (ONETT): 5th day after the close of the month of the instrument.
Check the calendar of legal holidays (national and any local holiday affecting your AAB/RDO).
Apply the next-business-day rule—move the deadline to the next working day.
Prepare and file the correct form (1706, 1707-A, 2000-OT).
Pay through an available channel (eFPS/online bank/AAB/RCO). Keep acknowledgment and payment confirmation.
Compile documents for CAR (when applicable).
Document any downtime or extraordinary events that impede timely compliance.

9) Frequent pitfalls (and how to avoid them)

Treating CGT and DST as a single deadline. They usually don’t match. Track both.
Confusing “execution date” with “transfer date.” For CGT/DST timing, instrument date/notarization drives deadlines more than later registry/transfer steps.
Assuming partial business days shift the deadline. Only full non-working days (weekends/holidays) push the due date; a short business day is still a business day.
Relying on courier or bank cutoffs without proof. Always secure electronic acknowledgments and official receipts that show when you actually filed/paid.
Overlooking local holidays where the RDO/AAB sits. If that office is closed, the next-business-day rule applies there.

10) Practical examples (quick reference)

CGT (property) due on Sunday → Pay Monday.
DST due on Saturday → Pay Monday.
Monday is a special non-working holiday → Pay Tuesday.
All systems down on Monday and BIR announces an extension to Wednesday → Filing/Payment by Wednesday is timely per advisory.

11) Records to keep

Filed returns (1706, 1707-A, 2000-OT) and acknowledgment/reference numbers.
Official receipts/bank confirmation with value date.
Deed/transfer documents and supporting papers used for valuation.
BIR advisories or screenshots evidencing any system issues around your due date.
CAR/eCAR and all transmittals.

12) Bottom line

If your CGT or DST due date falls on a weekend or holiday, Philippine tax administration recognizes the next working day as on-time for both filing and payment. Track each tax’s own deadline, plan your channel of payment, and keep documentary proof. Doing so preserves your right to the next-business-day leeway and shields you from surcharge, interest, and processing delays (especially for CAR).