A formal supplier document attesting that delivered materials or products meet specified requirements, drawings, and standards.
A **certificate of conformance** (CoC) is a formal document issued by a supplier or manufacturer stating that delivered materials, components, or finished products meet the requirements defined in an order, contract, drawing, or specification.
It is typically a signed statement that:
– Identifies the product or lot (for example, part number, batch number, quantity).
– References the applicable specifications, standards, drawings, or purchase order.
– Declares that the supplied items conform to those stated requirements.
– Is authorized by a qualified representative of the supplying organization.
A certificate of conformance is usually a **declarative attestation**, not a detailed test record.
In industrial and regulated environments, a certificate of conformance commonly:
– Travels with incoming materials or outsourced operations back into the plant.
– Is referenced in receiving inspection, quality release, and lot genealogy records.
– Serves as part of the device or batch history (for example, for traceability and investigations).
– Is controlled and retained under document control and record retention procedures.
CoCs may be required by contracts, customer quality agreements, or internal procurement policies, especially for:
– Critical raw materials and components.
– Contract-manufactured subassemblies.
– Calibrated instruments and certain maintenance services.
In a manufacturing IT/OT context, a certificate of conformance may be:
– Captured as an **electronic record** linked to material lots or serial numbers in MES or ERP.
– Referenced in **electronic batch records** or device history records.
– Exchanged electronically with suppliers or customers alongside limited MES-derived information (for example, release status or key quality attributes), where the CoC acts as the supplier’s formal attestation of conformance.
When MES data is shared externally, the CoC remains the contractual declaration of conformance, while MES data provides supporting context such as:
– Relevant test results summaries.
– Release or hold status for specific lots.
– Traceability links (for example, which supplied lot is used in which finished product).
A certificate of conformance:
– **Is not** usually a full test report or certificate of analysis (it normally does not list all measured values).
– **Is not** itself proof that tests were performed; it is an attestation that requirements were met.
– **Is not** a regulatory approval, license, or certification granted by an authority.
– **Does not** by itself demonstrate process validation or equipment qualification.
In some industries, the term **certificate of compliance** is used similarly; local procedures and contracts define the exact scope and content.
The term is often confused with:
– **Certificate of analysis (CoA):** Typically includes specific test results and measured values for a lot. A CoC usually only states that requirements were met, without listing all data.
– **Regulatory certificates or approvals:** Such as product certifications from a notified body or standards organization. A CoC is issued by the supplier, not by an external authority.
Understanding how a certificate of conformance differs from these documents is important when defining supplier documentation requirements and when linking documents into MES, ERP, and quality records.