A certificate of analysis (CoA) documents the actual test results for a specific batch against its agreed specification - the practical evidence that quality-control testing has been carried out and the batch meets the requirements you've agreed with your manufacturer.
Key points
- A certificate of analysis should reference the specific batch number, the parameters tested, the actual results, and the specification limits they're measured against.
- CoAs support batch traceability, and are often required documentation for your own downstream customers or regulatory obligations.
- The specific content and format of a CoA should be agreed with your manufacturer, since expectations vary by product and industry.
- A CoA is distinct from a safety data sheet - one documents batch-specific test results, the other communicates the product's general hazard and handling information.
What a Certificate of Analysis Typically Contains
A CoA typically includes the batch or lot number, manufacturing date, the specific parameters tested (such as concentration, purity, physical properties), the actual results, and the specification range each result is measured against, along with a statement confirming the batch's overall pass/fail status.
Who It Applies To
Producing a CoA is the manufacturer's responsibility, but agreeing what it should contain, and confirming you'll receive one with every batch, is something to establish explicitly with your manufacturer before production begins.
What This Means for Contract Manufacturing
Ask to see a sample certificate of analysis from a prospective manufacturer before committing, to confirm it captures the specific parameters that matter for your product - see quality-control testing and batch traceability for the underlying practices this document reflects.
What Should Appear on It
A useful certificate of analysis identifies the product and the specific batch, states each tested parameter with its specification limits and the actual result obtained, gives the date of manufacture or testing, and carries authorisation by whoever released the batch. Results should be actual measured values rather than a bare statement of conformity, because a value near the edge of a specification tells you something a simple pass does not.
Watch for certificates that report "conforms" against every parameter without figures, or that appear identical batch after batch. Genuine measurement varies within a specification range; results that never move suggest the figures are being carried across rather than generated. Either pattern is worth querying.
Agreeing the Content in Advance
Manufacturers test what the agreed specification requires. If a property matters to you and is not on the specification, it will not be tested and will not appear on the certificate - and discovering that after delivery is a poor moment to raise it. Settle the certificate's contents when the specification is agreed, as part of the quality agreement.
It is also worth agreeing the format and how the certificate is delivered, particularly if you need to pass it to your own customers. A certificate that arrives days after the goods, or in a form you cannot forward, causes friction that is easily avoided by specifying it up front.
Keeping Them
Certificates of analysis are part of the evidence trail. Retained alongside batch traceability records, they allow a later question about a specific consignment to be answered from what the material actually measured at release, rather than from recollection. Keep them for at least the product's shelf life plus a margin, and make sure you can retrieve them by batch number.
When the Certificate Disagrees With Your Own Testing
If you test incoming material and get a different result from the certificate, the usual cause is method rather than material - different equipment, different sample preparation, different temperature. Agreeing the test method in the specification prevents most of these disputes before they start, and where a genuine disagreement persists, referring a sample to an independent laboratory is the normal way to resolve it. Agree that route in advance rather than negotiating it mid-argument.
Related Pages
Frequently Asked Questions
Is a certificate of analysis the same as a safety data sheet?
No - a CoA documents batch-specific test results against your specification, while a safety data sheet communicates the product's general hazard, handling and safety information. See safety data sheets for that document specifically.
Should we receive a certificate of analysis with every batch automatically?
This should be agreed explicitly with your manufacturer rather than assumed - some manufacturers provide it as standard, others only on request, so confirm this as part of your quality agreement.
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Search the DirectoryLast reviewed: August 2026. Regulation and guidance change — verify anything you rely on against the primary source. Tell us if something here is out of date.