BIR Compliance for Startups in the Philippines: The Filing Calendar and What It Does to Your Cash

Most guides to BIR compliance are written for the person doing the filing. This one is written for the founder paying for it. The filings themselves are usually handled by a bookkeeper or an accounting firm. What lands on the founder is the cash: a cluster of payments that arrive on a calendar the bank balance knows nothing about.

So this post does two jobs. It lays out what a typical early-stage corporation owes the BIR and when, and it shows where each obligation belongs in a forecast. Rules were checked against 2026 tax calendars from Philippine firms in October 2026. Deadlines shift with revenue issuances and eFPS groups, so confirm the exact dates with the BIR or your accountant before you rely on them.

What you sign up for the day you register

Registration with the BIR gives you a TIN, a Certificate of Registration (Form 2303) listing the taxes you are registered for, and an obligation to keep books of accounts. Books can be manual, loose-leaf or computerised, and they are registered with the BIR, increasingly through its online system, ORUS.

The Certificate of Registration matters more than founders expect. It lists every tax type you must file for, and a return is due for each one even in a month with nothing to report. A zero return is still a return. Missing one carries a penalty whether or not any tax was owed.

The monthly rhythm: withholding

From the first payroll, you are a withholding agent. Tax withheld from salaries is remitted monthly, around the 10th of the following month for manual filers, with eFPS filers on staggered dates a few days later. Expanded withholding on payments to suppliers, landlords and contractors follows a similar monthly rhythm in the first two months of each quarter, with a quarterly return closing it out.

For the forecast, withholding is not a new cost. It is money you already deducted from someone else's payment and are holding for the government. The mistake is to treat the full gross salary as gone on payday. Part of it leaves on the 10th of the next month. Model the timing, not just the amount, and the cash line stops jumping for no visible reason.

Payroll also carries SSS, PhilHealth and Pag-IBIG contributions. We compared those with the rest of the region in employer contributions across Southeast Asia.

The quarterly rhythm: income tax and business tax

Quarterly income tax returns are due within 60 days after the close of each of the first three quarters. A startup still making a loss usually pays little or nothing here, but the return is still filed.

Business tax depends on whether you are VAT registered. Above PHP 3M in annual gross sales, VAT at 12% applies and is filed quarterly. Below it, most small companies pay percentage tax at 3% of gross sales instead, also quarterly. Many B2B startups register for VAT early because their customers want VAT invoices, which moves them into the quarterly VAT cycle before the threshold forces it.

For the forecast, output VAT is the one that surprises people. It sits in your bank account between the day the customer pays and the day the return is due, and it looks like revenue. It is not. A ledger that books VAT to a liability account shows you the real cash position. A bank balance does not.

The annual rhythm: the April cluster

For a calendar-year company, the annual income tax return is due on the 15th day of the fourth month after year end, so mid-April. Audited financial statements go with it, and they go to the SEC as well on its own schedule. The annual information returns for withholding, and the certificates you give employees, fall due in the first quarter too.

Two rules matter once you start growing. Domestic corporations with net taxable income of PHP 5M or less and total assets of PHP 100M or less, excluding land, are taxed at 20% rather than the standard 25%. And from the fourth taxable year after you start operations, a minimum corporate income tax of 2% of gross income applies if it is higher than the regular tax. A company that is still loss-making in year four can owe income tax for the first time without having made a profit. Put the year it starts in the forecast now.

Where each obligation belongs in the forecast

The practical move is to forecast tax as a liability that builds and then clears, not as an expense that appears on the day you pay it.

• Withholding: accrue it with payroll and supplier payments, clear it the following month.
• VAT or percentage tax: accrue it from sales, clear it the month after each quarter ends.
• Income tax: accrue it quarterly against your forecast profit, clear the annual balance in April.
• Fees for the audit and the filings: add them to the months they are actually invoiced, not spread evenly.

This only works if the forecast reads from books that are current. A ledger closed a month late tells you about April in May. We covered why that lag happens in why your management report is always three weeks late, and how to set up the monthly cycle that prevents it in the finance operating rhythm for a pre-seed company.

What to ask your bookkeeper for

You do not need to file any of this yourself. You do need three things from whoever does:

1. A list of every tax type on your Certificate of Registration and the date each return is due for the next twelve months.
2. Monthly balances for withholding, VAT or percentage tax and income tax payable, in the same report as the P&L.
3. A note of anything filed late, and the penalty, in the month it happened.

If those three arrive every month, the tax calendar becomes a line on your forecast instead of a surprise in your bank account. For the wider planning picture in the Philippines, see financial planning for B2B startups in the Philippines.

Takeaway

BIR compliance for a startup is a calendar: monthly withholding, quarterly income and business tax, and an April cluster that brings the annual return and the audit together. None of it is unusual, and most of it is handled by your bookkeeper. What founders miss is that every one of those payments is a liability building up in the books long before it leaves the bank. Forecast from the ledger, not the bank balance, and April looks like every other month.