Certificate of conformance: required fields and checklist
Know what a certificate of conformance must contain, when it can replace inspection, and how a distributor's certificate differs from the manufacturer's.
Where your quality system allows it, a certificate of conformance lets receiving accept a shipment on the supplier's signed word instead of inspecting every lot. A buyer who writes a specific certification requirement onto the PO, and a receiving clerk who checks the certificate against it, catches a missing signature or the wrong revision before the parts reach the line. A vague or unsigned certificate does the opposite: the lot sits on hold, or gets accepted on faith.
What is a certificate of conformance?
A certificate of conformance is a supplier's signed, written statement that a specific shipment meets its purchase order, specifications and their revisions. It is the supplier's own promise, and it does not replace receiving inspection unless the contract says so.
A single certificate can cover one line item or an entire shipment. Its value depends on what it names: the part, the revision, the quantity and the signer.
What must a usable certificate of conformance contain?
A usable certificate of conformance ties five things together: the purchase order number, the part number and revision, the quantity shipped, the lot or serial number, and the specifications the parts were built to, with their own revisions. An authorized person signs and dates it. Skip one, and receiving cannot match the certificate to the shipment in hand.
What a usable certificate of conformance contains
A six-row checklist table of the fields a certificate of conformance needs. Purchase order number ties it to one transaction; a missing PO number or an outdated PO revision is a common defect. Part number and revision confirm the version shipped; giving a part number with no revision is a common defect. Quantity lets receiving reconcile the certificate against the shipment; a mismatch with the packing list is a common defect. Lot or serial number lets a later nonconformance be traced to the affected units; having none forces a hold on every lot the certificate could cover. Specification and its revision state exactly what standard the parts were built to; a generic statement naming no document is a common defect. Signature and date of an authorized person identify who is making the statement and when; an unsigned, undated, or unauthorized signature is a common defect.
| Field | Why it matters | Common defect |
|---|---|---|
| Purchase order number | Ties the certificate to one commercial transaction and its terms | Missing, or references an earlier PO revision |
| Part number and revision | Confirms the certificate matches the part and drawing version actually shipped | Part number given with no revision, or the revision on file has since changed |
| Quantity | Lets receiving reconcile the certificate against what physically arrived | Certificate quantity doesn't match the packing list or the PO line |
| Lot or serial number | Lets a later nonconformance be traced to exactly the units affected | No lot or serial number, so a failure forces a hold on every lot the certificate could cover |
| Specification and its revision | States exactly what standard the parts were built to, not a general claim | A conformance statement naming no document, such as "meets all applicable requirements" |
| Signature and date of an authorized person | Identifies who is making the statement, and when | Unsigned, undated, or signed by someone without the authority to certify |
Each field answers a question receiving needs answered before it can accept the shipment on the certificate alone.
That lot or serial number is also what makes traceability to raw materials possible once the parts are in stock. A special processor's certificate of conformance can also serve as evidence in a first article inspection package.
When does a certificate of conformance replace inspection?
A certificate of conformance replaces inspection only when the buyer's quality system or the supplier agreement allows it, usually for a defined class of parts, or for suppliers with a good record. The certificate does not waive the buyer's right to inspect; that right comes from the contract or the governing law, not the certificate.
Accepting on a certificate can shorten what the buyer can still reject later. Some laws treat goods as accepted if the buyer doesn't inspect and give notice promptly, except for hidden defects, so check the contract, governing law and counsel before skipping inspection.
In the United States
On a US government contract, a certificate of conformance can replace source inspection only when the contracting officer decides acceptance on that basis serves the government's interest, and either a defect would cause only a small loss or the contractor's record makes acceptable supplies likely, with any defective work replaced, corrected or repaired without contest. FAR 46.504. The contracting officer inserts the clause at FAR 52.246-15 when those conditions apply. FAR 46.315. The supplier then ships on a certificate only after the cognizant contract administration office authorizes it in writing, or after inspection and acceptance happen first, and the certificate itself uses the wording prescribed in FAR 52.246-15(d), signed with the signer's title. The government keeps the right to reject defective supplies within a reasonable time after delivery, by written notification.
What other documents get mistaken for a certificate of conformance?
Two documents look similar to a certificate of conformance but carry different legal weight: a manufacturer's regulatory declaration that a product meets the law of the market it's sold in, and an aviation authority's release certificate. Both attest to something beyond a purchase order, and neither stands in for the commercial certificate your quality clause asks for.
Selling into the EU?
In the EU, a manufacturer places CE marking only after drawing up an EU declaration of conformity, a document under the New Legislative Framework whose model structure is set out in Decision No 768/2008/EC, Annex III, and repeated in each product law that requires CE marking. It states that the manufacturer takes sole responsibility for the product's conformity with the applicable EU legislation, a different scope than one buyer's purchase order. EU harmonisation law doesn't require a supplier to certify conformance to a buyer's purchase order. The vehicle "certificate of conformity" under Regulation (EU) 2018/858, Article 36 is a different document: it states that a finished vehicle matches its approved type. ISO/IEC 17050-1 gives a general structure a supplier can use for its own declaration of conformity. Under German commercial law, a merchant buyer who doesn't inspect and give notice without undue delay is treated as having approved the goods, except for hidden defects. § 377 HGB.
Selling into the EU?
In EU aerospace supply chains, an approved production or maintenance organisation releases parts with an EASA Form 1, issued under Part 21 of Regulation (EU) No 748/2012. For an airworthiness release, the Form 1 states that the part was produced in conformity with approved design data and is in a condition for safe operation, a broader and more specific statement than a commercial certificate of conformance. EASA FAQ: What is an EASA Form 1? A buyer's quality clause can ask for both: the Form 1 for airworthiness release, and a certificate of conformance for the purchase order's own requirements. Under the US-EU aviation safety agreement, EASA accepts an FAA Form 8130-3 as equivalent to a Form 1 for new parts, and for used parts when it carries a dual release. EASA FAQ.
How does a certificate of conformance differ from a certificate of analysis and a mill test report?
A certificate of conformance states that the shipment meets the spec, without necessarily giving test data. A certificate of analysis reports measured values for the batch actually tested, against defined limits. For metals, EN 10204:2004 defines the inspection documents commonly called mill test reports, in four types.
EN 10204:2004 sets four document types. Types 2.1 and 2.2 are the manufacturer's own statement, with 2.2 adding non-specific test results. Type 3.1 reports specific tests on the delivered product, validated by an inspector independent of manufacturing, and 3.2 adds a second validation by the purchaser's or an officially designated inspector.
C of C, certificate of analysis and mill test report compared
A three-row matrix comparing a certificate of conformance, a certificate of analysis, and a mill test report under EN 10204. The certificate of conformance is issued by the supplier and states the shipment meets the purchase order and named specifications, without necessarily giving measured values. The certificate of analysis is issued by the supplier or its lab and reports measured results for the specific batch tested against defined limits, but doesn't establish that the tested batch is the one shipped unless lot numbers tie them together. The mill test report is issued by the material producer under EN 10204, at one of four document types: 2.1 and 2.2 are the manufacturer's own statement, and 3.1 and 3.2 are validated by an inspector independent of manufacturing, with 3.2 adding a second validation by the purchaser or an officially designated inspector; it says nothing about what happens to the material after it leaves the mill.
| Document | Who issues it | What it states | What it doesn't state |
|---|---|---|---|
| Certificate of conformance | The supplier | The shipment meets the purchase order and named specifications | Actual measured values; it is a statement, not test data |
| Certificate of analysis | The supplier or its lab | Measured results for the specific batch tested, against defined limits | Whether the batch shipped is the one tested, unless lot numbers tie them together |
| Mill test report (EN 10204) | The material producer | One of four types: 2.1/2.2 are the manufacturer's own statement, and 3.1/3.2 are validated by an inspector independent of manufacturing, with 3.2 adding a second validation by the purchaser or an officially designated inspector | Anything about what happens to the material after it leaves the mill |
A certificate of conformance is a statement; a certificate of analysis and a mill test report carry measured data, validated to different degrees under EN 10204.
The metals side of that comparison, including which EN 10204 type a spec should call out, is in mill test reports.
What should the purchase order require, and who signs?
A purchase order should name its certification requirement by document: the specification and revision, the characteristics the certificate has to cover, and, for a distributor's shipment, whether the manufacturer's own certification has to come with it. A phrase like "per applicable requirements" leaves the supplier to decide what that means.
AS9100 and ISO 9001 each carry a clause on what an organization has to communicate to an external provider before the order goes out, covering approval of products and processes, and any verification the buyer or its customer will perform at the supplier. AS9100D, clause 8.4.3. ISO 9001:2026, clause 8.4.3. The certificate itself needs a signature from someone with the authority to make that statement for the company, usually a name the buyer already has on file from the supplier's quality organization.
How does a distributor's certificate of conformance differ from the manufacturer's?
A distributor's certificate of conformance states what the distributor observed: that the parts arrived from a named source and were stored and shipped as ordered. It cannot certify what happened on the manufacturer's floor, because the distributor wasn't there. A distributor's certificate should carry, or point to, the original component manufacturer's own certification, or a traceable chain back to it.
Without that link, a buyer has one company's word about another company's process. A buyer with a counterfeit-avoidance program checks lot and date codes against the manufacturer's markings at receiving.
Why do certificates get rejected at receiving?
A certificate gets rejected when it can't be matched to the shipment in hand: a missing purchase order number, a revision that doesn't match the drawing on file, a lot or serial number that isn't on the parts, or a conformance statement so generic it names nothing. An unsigned or undated certificate fails for the same reason.
Receiving should hold the lot when it cannot verify the certificate against the purchase order and the part's own marking. Your team can open each corrected-certificate request as a task and hand it to Scout Agent, who follows up with the supplier by email and phone. Receiving inspection sets out the hold decision.
What happens when a certificate of conformance turns out to be false?
Signing a certificate of conformance that isn't true is a false statement about the product, made by someone with the authority to bind the company. Supply contracts often let the buyer reject, charge back or terminate for a false certificate, on top of whatever the underlying nonconformance already costs. Check your contract and counsel.
In the United States
On a US government contract, a false certificate of conformance can expose the signer and the company to prosecution under 18 U.S.C. 1001, which makes it a crime to knowingly and willfully make a materially false statement or use a false writing in a matter within federal jurisdiction, punishable by a fine, up to five years in prison, or both. Where the false certificate leads to a false claim for payment, a false record material to that claim can also support civil liability under the False Claims Act, 31 U.S.C. 3729(a)(1)(B), (b)(1), which reaches a false record made knowingly, in deliberate ignorance, or in reckless disregard of the truth.
Questions teams ask
Can a buyer accept a certificate of conformance instead of incoming inspection on a commercial contract?
Yes, if the buyer's own quality system allows it, and the customer's flowdowns don't require inspection or source inspection, for that part or supplier class. That permission comes from the buyer's own procedure or the supplier agreement, not the certificate itself, and it can be withdrawn for a supplier whose certificates start missing detail.
Does a certificate of conformance need to list test results?
No. A certificate of conformance is a statement of conformity, not a test report. Where the specification calls for measured values, ask for a certificate of analysis or, for metals, a mill test report at the EN 10204 type your quality clause names, alongside the certificate of conformance.
Who can sign a certificate of conformance?
Someone with the authority to make that statement for the company, typically a quality manager or a named quality representative the buyer already recognizes. A certificate signed by someone without that authority, such as a shipping clerk, can be rejected.
Can a distributor issue its own certificate instead of passing along the manufacturer's?
A distributor can certify what it did: receiving, storing and shipping the parts as ordered. It should reference or include the manufacturer's own certification alongside that.
If incomplete certificates keep holding shipments at receiving, talk to our team about having Scout Agent follow up with suppliers for corrected certificates.
This article is general information, not legal or tax advice. Check how the rules apply to your business with your legal or tax advisor.
Sources (16)
- FAR 52.246-15, Certificate of Conformance
- FAR 46.504, Certificate of conformance
- FAR 46.315, Certificate of conformance
- Acquisition.gov, FAR Overhaul Part 46 deviation guide (confirms 46.315/46.504/52.246-15 numbering unchanged)
- 18 U.S.C. 1001, Statements or entries generally (uscode.house.gov)
- 31 U.S.C. 3729, False claims (uscode.house.gov)
- § 377 HGB, Commercial Code (Germany)
- Decision No 768/2008/EC of the European Parliament and of the Council, Annex II and Annex III
- Regulation (EU) 2018/858, Article 36 (vehicle certificate of conformity)
- ISO/IEC 17050-1:2004, Conformity assessment — Supplier's declaration of conformity — Part 1: General requirements
- Regulation (EU) No 748/2012 laying down implementing rules for airworthiness and environmental certification ('Part 21')
- EASA, FAQ: What is an EASA Form 1?
- EASA, FAQ: FAA/EASA reciprocal acceptance of release documents
- SAE AS9100D, Quality Management Systems — Requirements for Aviation, Space and Defense Organizations
- ISO 9001:2026, Quality management systems — Requirements
- BS/EN 10204:2004, Metallic products — Types of inspection documents