CBD COA: how to read a certificate of analysis before buying wholesale

By Manon, CBD specialist at Deli Hemp Pro

Updated 22 October 2026.

A COA (certificate of analysis) is the lab report for one specific batch. For a retailer, it is the only proof that the product on the shelf matches what is claimed, THC included. You still have to read it properly: a misread COA gives false comfort.

Here are the points to check, in the order they appear on most certificates.

Who ran the analysis, and is the lab accredited?

The laboratory's name and address should sit at the top of the document. Then look for ISO/IEC 17025 accreditation covering the method used. It is granted by a national body: UKAS in the UK, COFRAC in France, DAkkS in Germany. An unaccredited lab is not necessarily a bad one, but its result carries less weight in a dispute. A PDF with no laboratory letterhead is worthless.

Does the batch number match what you received?

This is the check most often skipped. The batch number on the COA must be the same as the one on the pouch, the supplier's label or the invoice. A “generic” COA, issued for a strain without any batch number, tells you nothing about your stock.

Look at the date as well. A year-old certificate for a batch that has just arrived deserves a question to the supplier: it may well cover another production run.

Which test method was used?

For cannabinoids, the reference method is liquid chromatography (HPLC or UHPLC). It measures the acid forms (THCA, CBDA) separately from the neutral forms (delta-9-THC, CBD). Gas chromatography (GC) heats the sample, which converts part of the acid forms, so it gives a result close to the total straight away. Both are in use; you just need to know which one you are reading.

How do you read the THC line?

An HPLC certificate usually shows three values: delta-9-THC, THCA and total THC. The total is calculated as follows:

Total THC = delta-9-THC + 0.877 × THCA

The 0.877 factor accounts for the mass lost when THCA turns into THC under heat. A batch showing 0.12% delta-9-THC and 0.40% THCA therefore has a total THC of 0.47%.

The 0.3% threshold that applies in France, and to hemp varieties grown in the EU, refers to delta-9-THC. For finished products, the limits and the way THC is counted vary from country to country, and some checks look at total THC instead. A batch close to 0.3% delta-9-THC with plenty of THCA deserves a careful look.

Mind the units too: 1% equals 10 mg per gram, so 0.3% is 3 mg/g. “ND” means not detected; “< LOQ” means present but below the limit of quantification. That limit is shown on the certificate.

What does a properly read certificate look like?

A fictional example, to show how to read a CBD flower report:

Which warning signs should worry you?

• No batch number, or a batch that does not match your goods.
• A lab you cannot trace, with no address or accreditation number.
• A date that is very old compared with the delivery.
• Suspiciously round figures (CBD 20.00%, THC 0.00%) or only one cannabinoid measured.
• A doctored PDF: mixed fonts, misaligned columns, a blurred logo.

If in doubt, ask the supplier for the original certificate, or contact the lab with the report number: most will confirm whether it is genuine.

Where can you find the lab reports for our products?

On the product pages that have one, the lab report can be downloaded as a PDF. For a product without a PDF, ask your sales contact for the batch report before you order. Then file each certificate by batch number, on paper or in a shared folder: it is the first document requested during an inspection. Our products comply with French law (delta-9-THC no higher than 0.3%). The rules for reselling hemp products differ from one country to the next, and the status of hemp flower and resin in the UK remains contested: check what you may sell locally before you order.

For resins sold as “THC-free”, the THC line is even more decisive. We explain why in our article on THC-free CBD resin.

Frequently asked questions

What is a CBD COA?

It is the certificate of analysis for a batch of CBD product, issued by a laboratory. It gives the measured levels of cannabinoids (CBD, THC, THCA and so on), the method, the date and the batch number. It lets a retailer check that the product received matches what was announced.

Is the COA supplied by the wholesaler enough?

Yes, provided it carries the number of the batch you received, the name of a traceable laboratory and a consistent date. A generic certificate with no batch, or one issued for another production run, proves nothing about your stock. If in doubt, the lab can confirm the report is genuine.

What does “ND” mean on a certificate of analysis?

“ND” means not detected: the method used did not find the compound. “< LOQ” means it is present but below the laboratory's limit of quantification. That limit is printed on the certificate, so you can judge how strict the test was.

How do you calculate the total THC of a CBD product?

Add delta-9-THC to THCA multiplied by 0.877: total THC = delta-9-THC + 0.877 × THCA. For example, 0.12% delta-9-THC and 0.40% THCA give a total THC of 0.47%, which is why both lines need reading together.