Below is a structured overview in the form of a legal-style article, reflecting general Philippine practice. It’s for information only and not a substitute for legal advice specific to your case.

I. SEC Approval vs. “Completion” of Company Registration

When the SEC issues your Certificate of Incorporation (or Certificate of Registration for an OPC or non-stock entity):

Your corporation acquires juridical personality.
The date on the SEC Certificate is your “Day 0” or “Incorporation Date”.
From that date, various statutory and regulatory timelines begin to run.

However, operating a business in the Philippines requires more than SEC approval:

National tax registration with the Bureau of Internal Revenue (BIR).
Local business permits from the city/municipality and barangay.
Social agency registrations (SSS, PhilHealth, Pag-IBIG) if you will hire employees.
Other sector-specific licenses (e.g., FDA, PEZA, DOLE permits for certain activities).

II. Overview of Typical Timeline After SEC Approval

Below is a common sequence after SEC approval (Day 0). Actual deadlines can vary by law, regulation, and local ordinances, but this is a useful working framework:

Day 0 (SEC Approval)
- SEC issues Certificate of Incorporation and related documents.
- Juridical personality begins.
Within ~0–30 days from SEC approval / before start of business
1. Register with BIR (obtain BIR Certificate of Registration, register books, apply to print official receipts/invoices or set up e-invoicing).
2. If shares have been subscribed and issued, compute and pay Documentary Stamp Tax (DST) on original issue of shares (file return after the close of the month when shares were issued).
3. Secure Barangay Clearance for business.
4. Secure Mayor’s/Business Permit from the city or municipality.
5. Register with SSS, PhilHealth, and Pag-IBIG Fund if you will employ people.
Before or shortly after commencement of operations
- Register establishment with DOLE (for employers).
- Obtain industry-specific permits (e.g., FDA for food/drugs/cosmetics, DENR for certain activities, BOI/PEZA for incentives, etc.).
Annually and periodically thereafter
- Renew business permits with LGU.
- File annual SEC reports (GIS, AFS).
- File BIR returns, update registrations if there are changes, and maintain compliance with DOLE and social agencies.

III. SEC Approval: What It Does and Does Not Cover

1. What SEC Approval Provides

Upon SEC approval, you normally receive:

Certificate of Incorporation (or OPC/Non-Stock registration certificate).
Approved Articles of Incorporation and By-Laws.
For corporations with shares:
- Details of the authorized capital stock.
- Named incorporators and directors.
For OPCs:
- Name of single stockholder and nominee/alternate nominee.

This gives you:

Juridical personality.
Capacity to enter into contracts (e.g., lease an office, open a bank account, etc.).
The ability to organize internally (appoint officers, adopt corporate policies, finalize share subscriptions).

2. What SEC Approval Does Not Automatically Provide

SEC approval alone does not:

Register you with the BIR.
Give you a Taxpayer Identification Number (TIN) (though some integrated systems may pre-assign one in practice, you still need to complete BIR processes).
Authorize you to issue official receipts/invoices.
Give you a Mayor’s Permit or barangay clearance.
Register you as an employer with SSS, PhilHealth, or Pag-IBIG.

Those are separate processes with their own timelines.

IV. BIR Registration: Timing and Key Steps

1. When to Register with the BIR

Under the National Internal Revenue Code (NIRC), any person liable to internal revenue taxes must register with the BIR on or before commencement of business. For corporations, a common interpretation and practice is:

You should register soon after receiving your SEC Certificate and before issuing any official receipts/invoices, opening the business to the public, or making taxable sales/leases.

Some Revenue District Offices (RDOs) also follow internal guidance treating 30 calendar days from SEC registration as a practical window. Regardless of internal practice, the safest approach is:

Register with the BIR promptly after SEC approval and before starting any business operations.

2. What Happens at BIR Registration

Typical outputs (may vary by RDO and current rules):

BIR Certificate of Registration (Form 2303) – showing:
- TIN (if not yet assigned).
- Type of taxes you are liable for (e.g., income tax, VAT or percentage tax, withholding tax on compensation, etc.).
Registered Books of Accounts
- Manual books (journal, ledger, etc.) stamped by BIR; or
- Approval for loose-leaf books; or
- Accreditation for Computerized Accounting System (CAS/CBA).
Authority to Print (ATP) or approval for e-invoicing
- If you issue printed invoices/receipts, you must secure ATP for official receipts (ORs) and sales invoices (SIs) and have them printed by an accredited printer.
- Under e-invoicing mandates, certain taxpayers must register and use electronic invoicing/reporting systems.
“Ask for a Receipt” or similar BIR notices
- Often required to be displayed at the business premises.

3. DST on Original Issue of Shares

If your corporation has issued shares (e.g., incorporators’ paid-in capital):

Documentary Stamp Tax (DST) is due on the original issue of shares of stock, based on par value or actual consideration.
By law, the DST return for such issuances is generally filed after the close of the month in which the taxable document (share issuance) was made, with payment within a short period thereafter (commonly described as within 5 days from the close of that month under existing regulations).
In practice, the DST on the initial capitalization is often settled soon after incorporation as part of the BIR registration process, to avoid penalties.

Late payment of DST triggers:

Surcharge (usually 25% or 50%, depending on the nature of the violation).
Interest and compromise penalties.

Because DST computation can be technical (especially if there are premiums, non-cash contributions, or multiple tranches of issuance), it is common to seek assistance from a tax professional.

V. Local Government Registrations: Barangay and Mayor’s Permit

1. Barangay Clearance for Business

Before obtaining a business permit from the city/municipality, you usually need a Barangay Clearance:

Obtained from the barangay where your principal office is located.
Common requirements:
- SEC documents (Certificate of Incorporation, Articles, By-laws).
- BIR TIN / proof of BIR registration (sometimes accepted later, depending on barangay).
- Lease contract or proof of ownership of the place of business.
- IDs of responsible officers, sketch of location, etc.

Timing:

Many LGUs require that you secure barangay clearance before you can apply for the Mayor’s Permit.
It is advisable to secure this before opening the office to the public or conducting onsite business operations.

2. Mayor’s / Business Permit

The Mayor’s Permit (or Business Permit) is the LGU’s primary business license:

Issued by the city or municipal government.
Quasi-universal requirement before a business can legally operate within that LGU’s territorial jurisdiction.

Typical requirements include:

SEC Certificate and Articles/By-laws.
BIR registration or TIN.
Barangay Clearance.
Lease contract or land title.
Occupancy permit or building permit, if premises are newly constructed or renovated.
Fire safety inspection certificate.
Sanitary or health permits for certain businesses.
Zoning/locational clearance.

Timing & renewals:

For new businesses, the permit should be secured before commencement of operations. Many LGUs will consider the business to be “operating without a permit” from the time it occupies the premises or begins sales, exposing it to fines and possible closure.
For renewals, LGUs typically require renewal in January of each year, with surcharges and penalties if not renewed within the prescribed deadline.

Consequences of delay:

Administrative fines and penalties.
Possible closure or padlocking of the establishment.
Inability to transact with government or certain private counterparties that require you to show a valid business permit.

VI. Registration with SSS, PhilHealth, and Pag-IBIG

If the company intends to hire employees, it must register as an employer with:

Social Security System (SSS)
PhilHealth
Pag-IBIG Fund

1. Timing

Best practice is to complete employer registration before or immediately upon hiring the first employee, so that you can:

Enroll employees and remit contributions from the first payroll cycle.
Avoid administrative penalties for late remittance or failure to register.

2. Key Points

Employers must deduct and remit contributions regularly, following each agency’s prescribed schedule.
Failure to register and remit contributions can result in:
- Penalties, surcharges, and interest.
- Possible civil and even criminal liability for responsible officers in serious or repeated cases.

VII. DOLE and Other Labor-Related Requirements

The Department of Labor and Employment (DOLE) requires establishments with employees to comply with various reporting and registration requirements, such as:

Establishment Report: Typically filed within a certain period after the start of operations or hiring employees (common practice is within 30 days).
Posting of labor-related notices and maintenance of employment records.
Compliance with occupational safety and health (OSH) standards (especially for factories, construction, and hazardous workplaces).
Company policies (handbooks, rules) consistent with the Labor Code.

These requirements are not always tied to a specific date like SEC issuance, but rather to:

The date the company starts operations, and
The date it hires employees.

VIII. Special Registrations and Licensing (Sector-Specific)

Depending on the nature of the business, additional post-SEC registrations may be required, such as:

Board of Investments (BOI) – For companies seeking investment incentives.
Philippine Economic Zone Authority (PEZA) – For ecozone locators.
Food and Drug Administration (FDA) – For food, cosmetics, drugs, medical devices, etc.
Bangko Sentral ng Pilipinas (BSP) – For financial institutions and certain fintech entities.
Insurance Commission, Energy Regulatory Commission, DENR, and many more, depending on sector.

These often have their own timing requirements, such as:

Application before starting regulated activities.
Registration within a specified period from incorporation or commencement.

IX. SEC Post-Incorporation Obligations and Annual Timelines

While the article focuses on timelines after SEC approval for initial registration, it is also important to remember ongoing SEC timelines, which start ticking after incorporation:

General Information Sheet (GIS)
- For stock corporations: typically filed within 30 days from the date of actual annual stockholders’ meeting.
- For non-stock corporations: based on their rules and SEC regulations.
Audited Financial Statements (AFS)
- Filed annually, within a prescribed period after the end of the fiscal year (e.g., 120 days or as SEC schedules provide, often staggered by last digit of SEC registration number).

Failure to file can lead to:

Monetary penalties.
Possible suspension or revocation of the corporate registration in severe cases.

These obligations sit on top of your tax filing and LGU renewal deadlines.

X. Consequences of Missing Post-SEC Registration Timelines

Missing the timelines for post-SEC registrations can have serious consequences:

BIR
- Compromise penalties and surcharges for late registration.
- Interest and penalties for late payment of DST and other taxes.
- Issues with claiming deductions or VAT input if documentation is not compliant.
LGU
- Fines for late application or renewal of permits.
- Business closure orders or padlocking of the premises.
SSS, PhilHealth, Pag-IBIG
- Penalties for late registration and contribution remittances.
- Personal liability of corporate officers in some cases.
DOLE and Sector Regulators
- Administrative penalties, suspension of operations, or disqualification from incentives.
Commercial Consequences
- Banks, clients, and counterparties often require valid BIR registration, business permits, and SEC good standing for:
  - Opening or maintaining bank accounts.
  - Bidding for contracts.
  - Entering into long-term leases or financing arrangements.

XI. Practical Sequencing Checklist

To visualize the timeline, a newly incorporated company might follow this practical order (all as soon as possible after SEC approval):

Immediately after SEC approval (Day 0–5)
- Secure official copies of SEC documents.
- Convene initial board meeting (if applicable) to elect officers, approve bank signatories, confirm capitalization.
- Start preparing BIR and LGU documentary requirements.
Within the first couple of weeks
- Register with BIR at the appropriate RDO.
- Register books of accounts.
- Apply for ATP or set up e-invoicing.
- Compute and arrange payment of DST on initial share issuance.
In parallel / shortly after
- Obtain Barangay Clearance.
- Apply for and secure Mayor’s/Business Permit.
- Open bank accounts and set up payroll systems.
Before hiring employees
- Register as employer with SSS, PhilHealth, and Pag-IBIG.
- Prepare company policies and employment contracts.
After operations begin
- Submit initial DOLE reports and continue complying with labor standards.
- Monitor and calendar annual SEC, BIR, and LGU reporting deadlines.

XII. Final Notes and Caution

The above timelines describe general Philippine practice and the typical sequence after SEC approval. Exact deadlines, forms, and procedures can change through new laws, revenue regulations, local ordinances, and administrative circulars.
Practices also differ among RDOs and LGUs, especially regarding documentary requirements and “grace periods”.
Because penalties for non-compliance can be significant, it is wise to:
- Maintain a compliance calendar for SEC, BIR, LGU, and labor/social agencies.
- Consult a Philippine lawyer or tax/accounting professional to tailor the timeline to your actual incorporation date, nature of business, and location.

Used properly, your SEC approval is the gateway to doing business—but only if you promptly and carefully complete the post-SEC registration timeline that the law and regulators require.