BIR Letter of Authority: What It Is and What to Do
Governing rule: RMO No. 6-2023 (as amended) — Priority Audit Case Guidelines
Legal basis: Section 6, National Internal Revenue Code of 1997 (Tax Code)
Keyword targets: BIR Letter of Authority Philippines, BIR audit, tax audit defense
You Just Received a BIR Letter of Authority. Now What?
A Letter of Authority (LoA) is one of the most consequential documents a Philippine taxpayer can receive. Issued by the Bureau of Internal Revenue (BIR) under Section 6 of the National Internal Revenue Code of 1997, an LoA is the formal authorization for a BIR revenue officer to examine your books of accounts and other accounting records for a specific taxable year. It is, in plain terms, the beginning of a tax audit — and how you respond in the first thirty days will significantly determine the outcome.
This article is written for business owners, CFOs, and finance managers who have just received an LoA and are deciding what to do next. The answer, briefly, is this: do not wait. Do not ignore it. And do not respond alone.
What the Letter of Authority Is — and What It Is Not
A LoA is issued by the Regional Director or the Commissioner of Internal Revenue (or their duly authorized representatives) and must identify: the taxpayer by name and TIN; the taxable year or period covered; and the revenue officer(s) assigned to the examination. A document without these elements may not be a valid LoA — and an examination conducted without a valid LoA can be challenged.
An LoA is not the same as a tax deficiency assessment. It is an authority to examine, not yet a finding of deficiency. Many audits result in no assessment, or in assessments significantly lower than the initial examination findings — but only if the taxpayer engages the process with the right documentation and the right legal counsel.
Why Businesses Get Selected
Why Was Your Business Selected for Audit?
Under RMO No. 6-2023, the BIR prioritizes audit cases based on a risk-based selection system. Common triggers include:
Discrepancies in filed returns — VAT returns that do not reconcile with income tax returns, or withholding tax remittances that do not match payroll records.
Low effective tax rate — Businesses in your industry paying significantly less tax than the industry average attract attention.
Large input VAT claims — Particularly from suppliers with a history of issuing fictitious receipts (those on the BIR's list of non-compliant taxpayers).
Third-party information — The BIR receives data from banks, the SEC, the BOC, and other government agencies. A significant bank deposit that does not appear in your income tax return is a known trigger.
Industry-specific campaigns — The BIR conducts industry-wide audit campaigns. If your industry is on the current campaign list, your selection may have nothing to do with a specific discrepancy.
Tip-offs and whistleblower reports — These are more common than most business owners realize.
Knowing why you were selected helps your counsel frame the appropriate response strategy from the outset.
The First 30 Days: Your Critical Window
1. Acknowledge receipt formally. The LoA will specify a period within which you must present your books and records. Acknowledge receipt in writing to the revenue officer. Never simply ignore the document or assume it will go away.
2. Identify the taxable year and scope. The LoA covers a specific period. Understand exactly what years and what taxes are being examined — income tax, VAT, withholding taxes, or all of the above.
3. Engage qualified tax counsel immediately. The examination process involves presenting documents, responding to queries, and — critically — making representations to the revenue officer about how transactions were treated for tax purposes. Every statement made to a revenue officer can and will be used in the assessment. This is not the stage for improvisation.
4. Gather and organize your records. The BIR will typically request: official receipts and sales invoices, purchase records and input VAT documentation, payroll records and withholding tax remittances, audited financial statements, BIR returns and proof of payment. Organize these by category and taxable year before the first meeting with the revenue officer.
5. Do not voluntarily expand the scope. Answer only what is asked. Do not proactively present records for years not covered by the LoA. Do not make representations about matters not yet under examination. Scope creep in a BIR audit is a real risk that competent counsel will help you manage.
What Not to Do - A Practical Don’ts List
Do not ignore it. An LoA that goes unanswered does not go away. The revenue officer will proceed to assess based on whatever information the BIR has — which is almost always less favorable than a properly documented response.
Do not deal with the revenue officer directly without counsel. Every statement you make — verbal or written — can be used to support an assessment. Revenue officers are trained examiners. You are not a trained taxpayer advocate. This is not the place to save on legal fees.
Do not offer informal settlements. Approaching a revenue officer with an offer to "settle informally" exposes you to extortion risk and potential criminal liability. All negotiations must go through proper channels — the Compromise Evaluation Board for assessments above the threshold, or the Administrative Protest process.
Do not destroy or alter records. Destruction of records under examination is a criminal offense under the Tax Code. Even records that are unfavorable to you must be preserved.
Do not assume a clean prior record protects you. The BIR examines the specific year in the LoA. A clean record for prior years is irrelevant to the current examination.
Do not sign a Waiver of the Statute of Limitations without legal advice. Revenue officers often request taxpayers to sign waivers extending the prescriptive period for assessment. Signing a waiver without understanding its implications can give the BIR years of additional time to assess — and a defectively executed waiver may itself be challenged to nullify the assessment.
The Assessment Timeline — Know Your Deadlines
Receiving a Letter of Authority is only the beginning. The BIR audit process moves through a series of formal stages, each with strict deadlines that cannot be missed. Understanding this sequence — and acting within each window — is the difference between a manageable tax matter and a final, unappealable assessment.
Stage 1 — The Examination (Letter of Authority)
Once the LoA is served, you are required to present your books of accounts and records within the period stated in the document — typically between ten (10) and thirty (30) days from receipt. The revenue officer will review your records, compare your filed returns against your supporting documents, and identify any discrepancies. This stage can take weeks or months depending on the complexity of your records and the scope of the examination.
Present books and records within the period stated in the LoA
All communications with the revenue officer should be in writing and coursed through your counsel
The examination must be completed within 120 days from the date of the LoA — if not, the LoA must be revalidated by the Regional Director before the examination can continue
Stage 2 — Preliminary Assessment Notice (PAN)
If the revenue officer finds a deficiency, the BIR will issue a Preliminary Assessment Notice setting out its initial findings. This is your first formal opportunity to correct the record.
You have 15 days from receipt to file a written Reply to the PAN
The Reply must address each finding specifically — a general denial is not sufficient
Documents submitted at this stage become part of the official record and will follow the case through protest and appeal
Missing this deadline does not automatically waive your rights, but it significantly weakens your position and may result in the BIR proceeding directly to the final assessment
Stage 3 — Final Assessment Notice / Formal Letter of Demand (FAN / FLD)
If the BIR is not satisfied with your Reply — or if you did not file one — it will issue a Final Assessment Notice and Formal Letter of Demand. This is the formal tax assessment.
You have 30 days from receipt to file a written Protest — either an Amended Return-Based Protest (Request for Reinvestigation) or a Protest based on existing records (Request for Reconsideration)
This is the most critical deadline in the entire process. Missing it renders the assessment final, executory, and demandable — meaning the BIR can proceed to collection without further court proceedings
The protest must be accompanied by all relevant supporting documents within 60 days from the filing of the protest if you filed a Request for Reinvestigation
Stage 4 — BIR Decision on Protest
After the protest is filed, the BIR has 180 days to act on it. Two scenarios follow:
If the BIR issues a decision denying or partially granting your protest, you have 30 days from receipt of that decision to appeal to the Court of Tax Appeals (CTA)
If the BIR does not act within 180 days, you may treat the inaction as a denial and appeal to the CTA within 30 days from the lapse of the 180-day period — or wait for the BIR to act, whichever comes first
Stage 5 — Court of Tax Appeals (CTA)
An appeal to the CTA is a full judicial proceeding. The CTA Division hears the case first, followed by the CTA En Banc on further appeal, and ultimately the Supreme Court if necessary.
The CTA is the specialized tax court of the Philippines and has exclusive jurisdiction over disputed BIR assessments above the jurisdictional threshold
Cases before the CTA are conducted like regular court proceedings — with pleadings, evidence, and oral arguments
CTA decisions carry the same weight as decisions of the Court of Appeals
One Rule Above All Others
Every deadline in this process is strictly enforced. The Supreme Court and the Court of Tax Appeals have consistently held that failure to protest a Final Assessment Notice within 30 days renders the assessment final and beyond judicial review — regardless of the merits of the taxpayer's position. There is no exception for good faith, ignorance, or financial difficulty.
If you have received any document from the BIR — whether a PAN, a FAN, or a demand letter — count the days from the date you received it and act immediately.
The Cost of Getting It Wrong - Penalties
The Cost of a Tax Assessment — What the BIR Can Impose
A BIR tax assessment is not limited to the principal amount of the deficiency. It typically includes:
Surcharge — 25% of the basic tax deficiency for ordinary cases; 50% for fraud, willful neglect, or false return.
Deficiency Interest — 12% per annum on the basic deficiency from the date the tax was due to the date of payment.
Delinquency Interest — An additional 12% per annum on the total unpaid amount (including surcharge and deficiency interest) from the date of the demand letter.
Compromise Penalty — A separate penalty for violations of the Tax Code, ranging from ₱1,000 to ₱50,000 depending on the nature of the violation.
A tax deficiency that looks manageable on paper can triple or quadruple once surcharges and compounding interest are applied — particularly if the assessment goes unprotested and the BIR proceeds to collection years later.
Official Sources
→ Bureau of Internal Revenue (BIR) — Official Website
→ BIR Revenue Memorandum Orders
→ National Internal Revenue Code (Tax Code)
RVTLC Practice Note: RVTLC & Associates Law Firm's tax practice is led by CPA-Lawyers with direct experience on both sides of the audit process — including partners who have managed BIR and BSP audit responses for multinational corporations, universal banks, and SMEs across multiple industries.
We represent clients at every stage: from the initial LoA response and records preparation, through the PAN reply and FAN protest, to appeals before the Court of Tax Appeals and the Supreme Court.
Our approach is direct: we review the LoA for validity, assess the likely scope and exposure, organize your documentation, manage all communications with the revenue officer, and build the strongest possible factual and legal record — because the protest you file today determines the case you can bring to the CTA tomorrow.
If you have received a Letter of Authority, contact us immediately at admin@rvtlc-law.com or call +63 917 874 3600. The first consultation is free. Time is your most critical resource — and it is already running.
