What Is a Manufacturer’s Affidavit and When Is It Required?

A manufacturer’s affidavit is a sworn written statement, signed by someone authorized to speak for a manufacturing company, confirming specific facts about a product: where it was made, what it contains, who built it, or whether it meets a particular regulatory standard. It carries legal weight because the signer declares the facts true under penalty of perjury, which means a false statement can bring criminal charges. You run into these affidavits in federal procurement, customs filings, vehicle titling, environmental compliance, and warranty disputes, often because they are the only document that will unlock duty-free entry, qualify a product for a government contract, or get an unusual vehicle registered.

How It Differs From a Certificate or Warranty

The oath is what sets a manufacturer’s affidavit apart from a routine Manufacturer’s Certificate of Origin, a product spec sheet, or a warranty card. Under federal law, an unsworn written declaration subscribed as true under penalty of perjury carries the same legal force as a traditional sworn affidavit, as long as it follows the prescribed form and is dated and signed.¹ That perjury exposure is what gives the document its teeth.

The signer has to be someone with authority to bind the company. For a corporation, that typically means a president, vice president, secretary, treasurer, or an employee holding a valid power of attorney, backed by a corporate certification confirming that person has knowledge of the relevant facts.² A shift supervisor’s signature on a shop-floor memo will not do.

When You Need a Manufacturer’s Affidavit

The affidavit surfaces wherever a government agency, contracting officer, or arbitrator needs more than the manufacturer’s casual word. The context shapes what the affidavit must say, but the underlying job is the same every time: sworn verification of facts the receiving party cannot independently check.

Returning U.S.-Made Goods and Country-of-Origin Claims

One of the most common triggers is bringing American-made goods back into the United States after they have been abroad. Under HTSUS subheading 9801.00.10, products of the United States can re-enter duty-free as long as they were not improved or increased in value while outside the country.³ For a shipment valued over $2,500, the importer must file two declarations: one from the foreign shipper confirming the goods were not altered abroad, and one from the owner, importer, or agent identifying the U.S. manufacturer by name and location and certifying the goods were exported without benefit of drawback.²

If U.S.-manufactured goods return more than three years after export and lack clear markings showing the manufacturer’s name and address, CBP may require additional documentation, including a statement from the manufacturer verifying domestic production.³

Separately, importers of foreign-made goods use manufacturer’s affidavits to certify country of origin. Every article of foreign origin entering the United States must be marked with the English name of its country of origin unless a statutory exception applies.⁴ A supporting affidavit helps substantiate the marking and claim preferential treatment under a free trade agreement.

Federal Procurement Under the Buy American Act

Selling manufactured goods to the federal government almost always means certifying domestic content. Under the Buy American Act, a manufactured end product qualifies as domestic only if the cost of its U.S.-made components clears a set percentage of total component cost. For items delivered in calendar years 2024 through 2028, that threshold is 65 percent, rising to 75 percent starting in 2029. Products made predominantly of iron or steel face a stricter rule: foreign iron and steel must account for less than 5 percent of total component cost.⁵

A manufacturer’s affidavit is the standard way to document that a product clears those thresholds. The manufacturer identifies the item, lists domestic and foreign component costs, and swears the calculations are accurate. Contracting officers rely on these affidavits because they have no practical way to audit a factory floor from a procurement office.

Specially Constructed Vehicles

When someone builds a vehicle from scratch, puts together a kit car, assembles a custom trailer, or finishes a homebuilt motorcycle, no traditional title exists. States handle this through a specially constructed vehicle process that generally requires a sworn statement documenting the origin of major components like the frame, body, and engine. The builder provides bills of sale, invoices, or other proof of legitimate purchase for each significant part. Once the vehicle passes a physical inspection, the motor vehicle agency assigns a new VIN and issues a title branded as specially constructed. The affidavit replaces the chain of title that would normally accompany a factory-built vehicle.

Specifics vary by state, including which components require documentation, the inspection fee, and the exact form used. Check with your state’s motor vehicle agency for the current requirements before you start assembling paperwork.

EPA Emissions Certification

Manufacturers of motor vehicles and engines must certify compliance with EPA emissions standards. An authorized company representative signs each submission to the EPA, certifying the information is accurate and complete. Production units must conform in all material respects to the configuration described in the certification application. During selective enforcement audits, the manufacturer must also submit a report attesting that testing followed regulatory requirements, that production processes and quality-control procedures have not changed in any way that could affect emissions, and that all information in the report is true and accurate.⁶

Lemon Law Arbitration

Manufacturer’s affidavits show up in lemon law arbitration and other warranty disputes too. When a consumer alleges a defective vehicle, the manufacturer often submits a sworn statement setting out its view of the vehicle’s repair history, specifications, and why it believes the vehicle does not qualify for replacement or repurchase. Because lemon laws are state-enacted, the precise role of the affidavit depends on the state’s arbitration rules. Some states also require the manufacturer to file a sworn certification of a vehicle’s repair status before reselling a reacquired lemon.

What the Affidavit Must Contain

Exact contents depend on the context, but a legally sufficient manufacturer’s affidavit consistently covers the same categories. Missing any of them can mean rejection by the receiving agency or, worse, an opening for the other side to attack the document’s reliability.

The full legal name and address of the manufacturing company.
The name and official title of the person signing, together with a statement of their authority to bind the company.
Product identifiers: model number, serial number, and any industry-specific identifier such as a Vehicle Identification Number for motor vehicles or a Hull Identification Number for watercraft.
Date and place of manufacture. For motor vehicles, the certification label must show the month and year work was completed at the main assembly plant.⁷
Compliance statements. For motor vehicles, that means conformity with the Federal Motor Vehicle Safety Standards in effect on the date of manufacture. For emissions-regulated products, conformity with the certified configuration. For customs, country of origin and the absence of foreign improvement.⁷
A closing perjury clause. The federal form prescribed by 28 U.S.C. § 1746 reads: “I declare under penalty of perjury that the foregoing is true and correct.”¹

The compliance statement is where most of the real work lives. A procurement affidavit has to break down component costs to prove the domestic content threshold is met. A vehicle manufacturer may need to certify conformity with dozens of individual safety standards. That is why manufacturer’s affidavits are rarely short documents.

How To Sign and Submit It

Execution is where the document actually becomes binding, and it is where people most often trip up.

Notarization vs. the Federal Unsworn Declaration

In many state-level contexts, the affidavit must be signed in the physical presence of a notary public. The notary verifies the signer’s identity with a government-issued photo ID, witnesses the signature, and affixes a seal and jurat.

For most federal purposes, though, you do not actually need a notary. Under 28 U.S.C. § 1746, wherever federal law or regulation calls for a sworn affidavit, an unsworn written declaration signed under penalty of perjury carries the same legal force. The signer includes the statutory language, dates it, and signs.¹ Customs declarations, EPA certifications, and other federal filings can often proceed without a notary appointment. The statute excludes depositions, oaths of office, and oaths required before a specified official other than a notary, but those exceptions rarely touch manufacturer’s affidavits.

State agencies run differently. A state DMV processing a specially constructed vehicle title may require traditional notarization regardless of the federal alternative. Confirm which authority will receive the document before you decide.

Where It Goes

Most receiving agencies want the original physical document rather than a copy. For customs filings, declarations supporting a duty-free claim under HTSUS 9801.00.10 are filed as part of the entry documentation.³ For vehicle titling, submission is usually in person at the motor vehicle agency. Keep a certified copy for your own records in either case; if the original goes missing in transit or gets misfiled, you avoid starting over.

What Happens if a Statement Is False

The penalties are serious and cut across criminal and civil law. Signing a manufacturer’s affidavit you know to be false is not a paperwork problem. It is a federal offense.

Anyone who knowingly makes a false statement or uses a false document in a matter within the jurisdiction of the federal government faces up to five years in prison and a fine under 18 U.S.C. § 1001.⁸ The federal perjury statute separately punishes anyone who willfully states material facts they know to be false while under oath, again with a five-year maximum.⁹ The person who signs bears personal liability. A corporate title does not shield the signer from prosecution.

In customs, submitting a false manufacturer’s affidavit to claim duty-free treatment or misstate country of origin triggers civil penalties under 19 U.S.C. § 1592, tiered by culpability:

Fraud: a penalty up to the full domestic value of the merchandise, regardless of whether any duties were actually lost.¹⁰
Gross negligence: the lesser of the domestic value or four times the unpaid duties, or up to 40 percent of dutiable value if no duties were affected.¹⁰
Negligence: the lesser of the domestic value or two times the unpaid duties, or up to 20 percent of dutiable value if no duties were affected.¹⁰

Which tier applies often turns on whether the company had compliance procedures in place and how quickly it caught the error. A manufacturer that spots its own mistake and self-reports fares far better than one CBP uncovers during an audit.

Fixing an Affidavit You’ve Already Filed

Mistakes happen. A component’s country of origin gets misidentified, a serial number is transposed, a compliance certification turns out to apply to the wrong model year. How you handle the correction matters a great deal for both legal exposure and penalty size.

For customs errors, the single most effective step is filing a voluntary prior disclosure with CBP before the agency finds the problem on its own. For violations involving negligence or gross negligence, a timely disclosure with payment of back duties typically limits the penalty to interest on the unpaid amount. Even for fraud, a prior disclosure caps the penalty at 100 percent of the unpaid duties rather than the full domestic value of the merchandise.¹⁰ The disclosure must be made before, or without knowledge of, the start of a formal CBP investigation.

For entries made on or after December 18, 2004, CBP itself cannot reliquidate an entry to fix a clerical error, mistake of fact, or inadvertent omission without a valid protest. The importer has to file a formal protest under 19 CFR Part 174 to get the correction processed.¹¹ This catches people off guard. An obvious typo does not get a quick administrative fix; the regulation requires the formal protest route.

Outside of trade, correcting a manufacturer’s affidavit generally means preparing and filing a new, accurate affidavit that supersedes the original. If you filed with a state motor vehicle agency, contact the agency to find out whether you need a corrective affidavit, a supplemental statement, or a fresh application. For EPA certification, errors must be corrected through amended filings to the relevant EPA office, and production must conform to the corrected certification in all material respects.⁶ Whatever the context, document the correction promptly and in writing. It protects you if the original error is later questioned.

1
Office of the Law Revision Counsel. 28 U.S.C. 1746 – Unsworn Declarations Under Penalty of Perjury
2
eCFR. 19 CFR 10.1 – Domestic Products; Requirements on Entry
3
U.S. Customs and Border Protection. Requirements for Importers and Brokers Regarding HTS Subheading 9801
4
U.S. Customs and Border Protection. Marking of Country of Origin on U.S. Imports
5
Acquisition.GOV. Subpart 25.1 – Buy American-Supplies
6
eCFR. 40 CFR Part 1068 – General Compliance Provisions for Highway, Stationary, and Nonroad Programs
7
eCFR. 49 CFR Part 567 – Certification
8
Office of the Law Revision Counsel. 18 U.S.C. 1001 – Statements or Entries Generally
9
Office of the Law Revision Counsel. 18 U.S.C. 1621 – Perjury Generally
10
Office of the Law Revision Counsel. 19 U.S.C. 1592 – Penalties for Fraud, Gross Negligence, and Negligence
11
eCFR. 19 CFR 173.4 – Correction of Clerical Error, Mistake of Fact, or Inadvertence