Affidavit of Alteration for a Sales Invoice (Philippines) A practitioner-oriented overview

1. What it is and why it exists

A Sales Invoice is an indispensable primary evidence of a sale of goods in the Philippines.¹ Once issued, it must mirror the particulars prescribed by the National Internal Revenue Code (NIRC) § 237, as elaborated in Revenue Regulations (RR) No. 18-2012, RR No. 10-2015 and their successors. Errors do happen—wrong quantity, mis-keyed unit price, transposed Taxpayer Identification Number (TIN), etc.

Because altering a BIR-registered invoice after the fact is, strictly speaking, a deviation from the format the Bureau approved, any correction has to be memorialised under oath. The instrument used is usually entitled “Affidavit of Alteration (or Correction) of Sales Invoice.” It explains the mistake, identifies the exact document affected, and affirms that no fraud or tax evasion is involved.

2. Legal anchors

Topic	Key provisions	Practical effect
Issuance & format of invoices	NIRC § 237; RR 18-2012	Prescribes content, serial numbers, security printing, BIR Authority to Print (ATP)
Books & records	NIRC § 235; RR 17-2013	Invoices form part of the taxpayer’s “books”; alterations must be traceable
False or altered receipts	NIRC § 264(a)	Using untruthful invoices is penalised—₱1,000 – ₱50,000 fine + 2 yr – 4 yr imprisonment
Perjury	Art. 183, Revised Penal Code	Sworn statements that are wilfully false expose affiant to criminal liability
Notarial rules	2004 Rules on Notarial Practice	Affidavit must be subscribed and sworn before a duly commissioned notary public

3. When an affidavit is (and is not) advisable

Common triggers

Typographical error (buyer’s name, address, TIN).
Pricing misprint discovered after issuance but before VAT/GST return filing.
Quantity or product description mistake that does not nullify the entire sale (otherwise an official cancellation & re-issuance is better).

Scenarios where a replacement invoice is preferable

The invoice was printed on the wrong series or without BIR ATP.
The seller decides to void the entire sale or issue a credit memo (e.g., goods returned).
VAT originally treated as zero-rated but later found standard-rated (requires new invoice).

Rule of thumb: If the error fundamentally affects the tax base or the “legitimacy” of the document, cancel and re-issue. If it is a clerical or minor computational slip, an affidavit of alteration suffices—backed by proper adjusting entries.

4. Essential contents of the affidavit

Title – “Affidavit of Alteration of Sales Invoice No. _____”
Affiant’s identity – Full name, civil status, citizenship, residence, and position (if a corporation).
Authority – Cite board resolution or Secretary’s Certificate if signing for a company.
Particulars of the invoice – Serial number, date, ATP details, name of buyer, and amount.
Nature of the error – Plain description (“unit price of Item A was printed as ‘₱1,000.00’ instead of ‘₱100.00’ due to typographical error”).
Correct figures/data – State the rectified amount or detail.
Statement of good faith & absence of fraud – A standard averment that the alteration is not intended to prejudice the government or any party.
Undertaking – That the affiant will reflect the correction in the books and tax returns and present the affidavit during any BIR audit.
Signature block – Over printed name.
Jurat – Notarial acknowledgement with Doc. No., Page No., Book No. and Series of the notary.

5. Step-by-step procedure (corporate taxpayer)

Draft the affidavit (usually by the accounting or legal department).
Secure board approval/Secretary’s Certificate (if required by internal policy).
Notarise before a notary public in the locality of principal office.
Annotate the original invoice: write “Altered per Affidavit dated _____” near the change. Never erase or strike through amounts.
Enclose a photocopy of the original invoice with the affidavit and keep both in the Sales Invoice file.
Post adjusting entry in the accounting system (debit/credit appropriate sales, VAT-payable, etc.).
File or retain – Generally the affidavit need not be submitted proactively to the BIR. It must, however, be presented on demand during audit investigations or Letter Notice (LN) verifications. Some Revenue District Offices (RDOs) informally request a copy “for record purposes”; comply if asked.
Update returns – If the correction changes VAT output or income tax base already reported, file an amended VAT return (BIR Form 2550M/Q) or income tax return with the adjusted figures. Attach the affidavit as supporting document.

6. Liability exposure & risk-management tips

Risk	Statutory penalty	Mitigation
Unaltered misstatement – issuing an invoice with wrong amount and not rectifying	NIRC § 264(a): fine + imprisonment	Detect errors early; institute post-printing review
Falsified alteration – affidavit hides a price reduction to evade VAT	NIRC § 248 (50 % surcharge), § 254 (tax evasion, 6 yr–10 yr jail)	Strong internal controls; segregation of sales & accounting
Perjury	RPC Art. 183: jail + fine	Ensure factual accuracy; route through compliance/legal head

Best practice checklist ✓ Use pre-numbered invoices from an accredited BIR printer. ✓ Implement a three-way match (sales order – delivery receipt – invoice) before release. ✓ Institute a cut-off (e.g., 24 hours) for requesting corrections. ✓ Maintain an Altered/Cancelled Invoice Logbook—BIR examiners look for this.

7. Sample template (for guidance)

AFFIDAVIT OF ALTERATION I, JUAN DELA CRUZ, Filipino, of legal age, married, with office address at 123 Pasig Blvd., Pasig City, after having been duly sworn, depose and say:

I am the duly authorised Finance Manager of ABC Manufacturing Corp. (“ABC”), holder of BIR Certificate of Registration No. 9RC-123-456-000, with principal office at …

On 03 June 2025, ABC issued Sales Invoice No. 012345 (ATP No. 2025-000111-000222) to XYZ Hardware Corp. for 50 pieces of Item X at ₱1,000.00 per piece.

Due to typographical error, the unit price was printed as “₱10,000.00” instead of “₱1,000.00,” resulting in an extended amount of ₱500,000.00 instead of ₱50,000.00.

Immediately upon discovery on 05 June 2025, no payment had yet been received and no VAT return had been filed for the period.

Accordingly, ABC hereby alters the said invoice to reflect the correct unit price of ₱1,000.00 and total of ₱50,000.00 plus 12 % VAT of ₱6,000.00.

This alteration is made in good faith and not for the purpose of evading any tax.

ABC undertakes to record the corrected figures in its books and to present this affidavit and supporting documents in any future BIR examination. IN WITNESS WHEREOF, I have hereunto set my hand this 06 June 2025 in Pasig City, Philippines. (signature) JUAN DELA CRUZ SUBSCRIBED AND SWORN to before me this … etc.

8. Frequently-asked questions

Question	Answer
Do I need BIR approval before notarising?	No. The affidavit is unilateral; no prior BIR endorsement required.
Can I just print a new invoice and ignore the old one?	Not recommended. The old invoice is already “issued” under § 237. You must either cancel it (with a cancellation affidavit) or alter it properly.
Does an affidavit of alteration affect withholding tax on purchases?	Potentially yes—if the selling price changes, the buyer’s expanded withholding tax (EWT) base also changes; buyer should obtain a copy of the affidavit.
How long should I keep the affidavit?	Same as invoices: 10 years from the last entry under NIRC § 235 (amended by CREATE Act).

9. Key take-aways

Alterations are permissible only for bona fide clerical mistakes; anything more substantial calls for cancellation and re-issuance.
The affidavit is your audit shield: without it, an examiner can treat the original, erroneous figure as unreported VAT or income.
Keep the process tight—draft, notarise, log, adjust books, and be ready to show the paper trail for ten years.

Disclaimer: This article is for general informational purposes only and does not constitute legal or tax advice. Consult a Philippine lawyer or certified public accountant for guidance tailored to your specific circumstances.

¹ In contrast, for services the primary document is the Official Receipt; the governing principles are parallel, but the statutory references are § 237 and RR 18-2012 as well.