You Received a BIR Letter. Now What?
Last updated: July 9, 2026Not every BIR letter is an audit. The most common ones a doctor receives are the softer kind: 1) First Notice, a letter flagging a mismatch between what you reported and what your affiliations reported, withheld, and remitted or 2) List of Stop-Filer Cases, a letter sent to remind the taxpayer that there are missing returns. A real audit only begins when you're served a Letter of Authority, the document that authorizes a named officer to examine your books. Whatever arrives, the rules are the same: read it carefully, note every deadline, keep your response in writing, and get help before you reply. Don't ignore it and don't panic.
First, figure out what kind of letter it is
The word "BIR" on an envelope triggers dread, but most letters aren't the feared full audit. A doctor is far more likely to receive a First Notice letter and/or List of Stop-Filer Cases letter. These are reconciliation requests, not assessments. You must cross-check the list with your filing records and present proof of payment or submission if you have already filed those forms. A genuine audit starts only when a Letter of Authority (LOA) is served. An assessment issued without a valid LOA is void.
If it's a Letter of Authority, what it means
A Letter of Authority names a specific revenue officer and authorizes them to examine your books for a stated year and tax type. A few things are worth knowing so you're not intimidated by the wrong details. The officer named on it must be the one who audits you; reassigning your case to a different officer requires a new LOA. The officer is expected to complete the examination within 180 days for a district-office case or 240 days for large taxpayers from the date of issuance.
The assessment sequence, and your deadlines
If an audit does find a discrepancy, it moves through a defined sequence, and each stage gives you a window to respond. Missing a window is how a manageable question becomes a fixed liability, so these dates matter more than almost anything else.
| Stage | What it is | Your window |
|---|---|---|
| Notice of Discrepancy | Invitation to a discussion of the findings | Discussion within 30 days of receipt |
| Preliminary Assessment Notice (PAN) | The BIR's initial proposed assessment | 15 days to respond in writing |
| Final Assessment Notice / Formal Letter of Demand | The formal assessment and demand | 30 days to file a written protest (Motion for Reconsideration – based on the existing records, or Additional 60 days (Motion for Reinvestigation) – if incase additional and new evidence will be submitted |
| Final Decision on Disputed Assessment | The BIR's final decision on your protest | 30 days to appeal to the Court of Tax Appeals |
A worked example: a mismatch letter
Dr. Aquino receives a First Notice Letter. The letter indicated that her professional income reported by her affiliation is higher than the income she declared on her tax return. This isn't an audit yet, it's a data-matching mismatch, and the usual cause is simple: 2307s she didn't fully capture. Her calm next step is to pull her records, reconcile her declared income against the hospitals' figures, and respond in writing with the explanation and any amended return, within the window the letter gives. Handled early, a mismatch letter is a reconciliation, not a crisis.
If you're asked for documents you don't provide
During an audit, if you repeatedly fail to produce the records requested, the BIR can escalate to a Subpoena Duces Tecum, a formal order to produce your books, usually after a first and a final notice. Ignoring that carries real consequences, including the BIR assessing you on the best information it can obtain. The lesson is the ordinary one: always respond in writing, on time.
Got a letter you don't understand? Send it to us. We'll tell you exactly what it is and what to do.
Talk to UsYour rights when a real audit begins
An audit is a process with rules, not an open-ended fishing trip, and knowing that changes how it feels. You're entitled to see a valid Letter of Authority before anyone examines your books, to be assessed only for the year and tax type it covers. You're also entitled to represent yourself through an accountant or lawyer, to respond in writing, and to appeal an adverse decision to the Court of Tax Appeals. The calm posture is neither to stonewall nor to over-share: answer what's asked, on time, in writing, with professional help, and hold the process to its own rules.
How far back can the BIR go?
Generally, three years from official deadline of the return in question, which is one more reason to keep clean records and file on time. In case of late filing, 3-year rule counts on the date of filing. But the window stretches to ten years where a return was falsely or fraudulently filed, or was never filed at all. That longer window is precisely why an unfiled year is worse than a filed-but-imperfect one, and why coming forward voluntarily is almost always the better position.
Frequently asked questions
Does a BIR letter always mean I'm being audited?
Can I just ignore a letter I think is a mistake?
Should I handle a letter myself?
How do I tell a Letter Notice from a Letter of Authority?
Sources and references
- National Internal Revenue Code, Secs. 6, 13 (examination and Letter of Authority), 203 and 222 (assessment periods), 5(C) and 266 (subpoena and penalties)
- Revenue Regulations No. 12-99, as amended by RR 18-2013 and RR 22-2020, on the assessment process (Notice of Discrepancy, PAN, FAN, FDDA)
- RMC No. 82-2022, on the removal of the 30-day LOA service rule; RAMO No. 1-2020, on audit completion periods; RMO No. 43-90 on Letters of Authority
Current as of July 2026.