A Certificate of Analysis is the document that turns a supplier's claim into something you can check. It is also the document most often reused, backdated or quietly swapped for a different batch's report — usually without anything on the page looking wrong. Here is what to actually look at.
First: does it belong to your goods?
This is the check that catches most problems, and almost nobody makes it. A COA describes one specific batch of material. If the lot or batch number on the certificate does not match the lot number on your packing list and on the bags themselves, the report is describing something else — possibly excellent material that you are not buying.
The failure mode is rarely dramatic. A supplier sends the report from a good batch tested some months ago, because it is the one they have as a PDF. Everything on it is true. It just has nothing to do with your container.
Ask for the COA with the lot number on it before the goods ship, then check that number against the bags on arrival. A supplier who can only produce the certificate after shipment, or whose lot number is blank, is telling you something.
Second: who issued it?
There are three broadly different documents that all get called a lab report, and they carry very different weight:
- —An in-house report from the producer's own laboratory. Useful for process control, but the party being tested is also the party doing the testing.
- —A report from a laboratory the exporter selected and paid for, independent of the producer.
- —A report from an inspection agency you appointed yourself — SGS, Bureau Veritas, Intertek or whoever you already use.
All three look similar at a glance: letterhead, parameters, results, a signature. The difference is who had an interest in the outcome. Most exporters forward whatever their factory gave them. We commission testing from a laboratory that we do not own and the producer does not own, and you are welcome to appoint your own inspector on top of that.
Third: which method was used?
A result without a method is not a result. For curcumin in turmeric, the method you want to see is HPLC. Colourimetric or spectrophotometric estimates exist, they are cheaper, and they do not measure the same thing with the same precision — but a certificate quoting one can look identical to a certificate quoting the other unless you read the method column.
The same applies across the panel. Moisture, heavy metals, pesticide residues, aflatoxins and microbiological analysis should each name a method, and each should name a unit. A figure with no unit beside it is not something you can act on.
Fourth: is the panel the right one for your destination?
A certificate can be entirely genuine and still be useless to you, because it tests for the wrong things. Import requirements differ by destination market and by product, and they change. A panel that satisfies one country's customs may be missing a parameter another one requires, and you will find out at the port.
We are not going to print a table of limits here, because a threshold quoted from memory on a website is exactly the kind of unverified claim this guide is warning you about. Confirm the current requirements for your own destination with your customs broker or competent authority, then tell your supplier the port before they quote — not after. Ours is a conversation we have before the quote goes out, so the panel is right the first time.
The short version
- —Lot number on the certificate matches the lot number on the goods.
- —Issued by a laboratory independent of whoever produced the material.
- —Every parameter names its method and its unit — curcumin by HPLC.
- —The panel covers what your destination actually requires.
Four checks, about two minutes. They will not tell you the goods are perfect, but they will tell you whether the document in front of you describes the goods at all — which is more than most buyers establish before paying.
If you want to see what ours look like, the quality and testing process walks through how a batch gets approved, and we will send the current report for either product on request.
Written by TrueOrigin Exports, a merchant exporter of Lakadong turmeric and aged black garlic. Every export lot is tested by an independent laboratory before it ships — see how that works.