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The official digital platform powered by The Anatomy of a BIR Audit. Whether navigating statutory deadlines in-house or collaborating directly with accredited tax consultants, defend your position with precision and law.

Self-Guided Compliance

Do It Yourself with Expert Guidance

For Taxpayers, Corporate Treasurers & In-House Accountants

Take charge of your audit defense responsibly. Follow strict statutory procedures, extract notice data from LOA/PAN/FAN with automated analysis, track prescriptive periods, and prepare structured replies without legal missteps.

  • Notice Analysis: Extraction of Revenue Officers, tax periods, and alleged discrepancies.
  • Prescriptive Period Clocks: Strict 15-day PAN and 30-day FAN/FLD countdown alerts.
  • Discrepancy Reconciliations: Benchmark BIR schedules against General Ledger, SLSP & 2307s.
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Accredited Advisory

Engage an Accredited Consultant

For High-Stakes Assessments, Contested Findings & Formal Protests

When potential tax liabilities require seasoned representation, connect directly with verified CPAs and tax attorneys. Obtain peer reviews of notice findings, formal protest preparation, and administrative representation.

  • Direct Case Sharing: Transmit notices and workpapers directly to accredited consultants.
  • Protest Preparation: Drafting for Requests for Reconsideration or Reinvestigation.
  • Client Confidentiality: Zero-knowledge AES-256 client vault safeguards sensitive records.
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The BIR Audit Administrative Timeline

Every phase carries non-extendible deadlines and specific statutory remedies under Philippine tax law.

Day 0 to 120 window

LOA Received

Verify electronic Letter of Authority validity, revenue officer authority, and the 120-day audit cycle under RAMO 1-2000.

RAMO 1-2000 · 120 Days
120days
30-day window

Notice of Discrepancy

Informal Conference phase. Reconcile Sales vs SLSP, Creditable Withholding Tax (2307), and General Ledger variances.

RR 18-2013 · Discussion
30days
15 days · strict

PAN Issued

Non-extendible 15 calendar days from receipt to submit a formal written reply addressing the preliminary findings.

Sec. 228 NIRC · Non-Extendible
15days
30 days to protest

FAN / FLD

Submit a formal protest (reconsideration or reinvestigation) within 30 days, followed by 60 days to submit supporting documents.

Sec. 228 NIRC · Formal Protest
30+60days
30 days to appeal

FDDA / Appeals

Upon receipt of the final decision: file a request for reconsideration with the CIR, or elevate the appeal to the Court of Tax Appeals (CTA).

Sec. 228 NIRC · CTA Appeal
30days
01 / 05

Core Systems for Tax Defense

Engineered to streamline evidentiary compliance, document security, and practitioner workflows.

01

Notice Analysis

Automated extraction of audit scope, taxable periods, named revenue examiners, and contested deficiency schedules from official BIR notices.

Notice ReaderAI extraction
02

Prescriptive Clock

Active monitors for non-extendible statutory deadlines, generating timely warnings prior to PAN, FAN, and evidentiary due dates.

PAN · FAN · FDDAHoliday-aware
03

Discrepancy Reconciliations

Upload worksheets (Excel/CSV) to match book values against BIR calculations. Identify cell-level variances across tax types.

Excel / CSVCell-level variances
04

Client-Side AES-256 Vault

Client records and case files are encrypted in the browser prior to transmission. No unencrypted audit data is held on the server.

Zero-knowledgeIn-browser
05

Transmittal Management

Maintain complete records of all documents submitted to the BIR, including receiving stamps, date proofs, and itemized checklist attachments.

Receiving stampsChecklists
06

Multi-User CPA Firm Workspaces

Dedicated workspaces for accounting practices with custom branding, case permissions (Edit, Encode, View), and client access portals.

Edit · Encode · ViewClient portals
The Anatomy of a BIR Audit - Book by Atty. Arnold A. Apdua, CPA
Official Digital Edition

Powered by The Anatomy of a BIR Audit

Authored by Atty. Arnold A. Apdua, CPA · Founder, Bizmaker Consultancy Inc.

The workflows, legal citations, and defense playbooks within BIR Audit Navigator are based directly on the authoritative reference treatise. From LOA examination to formal protest and CTA appeal, navigate each phase with battle-tested tax jurisprudence.

Have the printed book? Its activation code gives you a free trial: every stage of an audit case you choose, for 3 days.
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Tax Code Aligned

Formulated around the National Internal Revenue Code, RR 12-99, RR 18-2013, RR 22-2020, and the Ease of Paying Taxes Act.

Zero-Knowledge Privacy

Local AES-256 browser encryption ensures case files and reconciliations are readable only by authorized firm and client members.

Philippine Sovereignty

Adherence to Republic Act 10173 (Data Privacy Act of 2012) and official BIR transmittal evidentiary protocols.

Consultant Network

Integrated access to verified tax attorneys and CPAs for independent evaluations, protests, and administrative defense.

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Managing an Active BIR Audit?

Whether reviewing an initial Letter of Authority or responding to a formal assessment within strict deadlines, safeguard your business with law and technological precision.

  • Every deadline computed from the Tax Code and its regulations
  • Files encrypted in your browser before they leave it
  • CPAs of the official firm one message away
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