Many people who buy CBD flowers have heard that it is important to check the certificate of analysis (COA); however, in our experience, most never do. The small number who do are met with a PDF document with figures and abbreviations that make little sense to them.

We'll show you how to read a CBD flower COA from a 2026 batch of Diesel CBD flower and cover the cannabinoid results.

Full COA for a 2026 batch of our Diesel CBD flower (lot DIES001K26), issued by Ambra srl on 14 April 2026. Click to enlarge.

What Is a CBD Flower COA?

A certificate of analysis (COA) is a laboratory report that lists what was measured in a sample of a product. A CBD flower COA mainly measures the cannabinoid content. Many CBD companies do not have in-house testing and commission laboratories to conduct lab tests of their products on their behalf. The 2026 batch of our Diesel CBD flower in this guide was tested by an Italian laboratory called Ambra. The test was commissioned by the company that submitted the sample.

The COA covers one sample from each batch and records the measurements found on that sample. The COA doesn't grade its quality or make guarantees about any pack or its legality.

COAs are useful for CBD flower buyers because they can be compared against the product listing. Our Diesel CBD flower listing says 8-13% CBD, and the COA shows total CBD of 12.93%.

Where Can You Find the COA for CBD Flower?

The COA should be easy to find on a CBD flower product page. On our site, scroll to 'Lab Results' under the description, click the link, and the lab's PDF will open up. The COA shown is for the current batch and is updated when new batches arrive.

Some sellers have a dedicated lab results page, so check the menu and footer as well, because it isn't labelled the same way everywhere. Make sure that you are looking at the original lab PDF, not a seller-written reproduction, and that the product name matches what you are buying.

If you can't find a COA for a CBD flower, ask the seller for it.

How Do You Read a COA That Isn’t in English?

Many CBD flower COAs come from labs outside the UK. The COA we'll be looking at in this article comes from Italy and is written in Italian. We'll translate any foreign terms with our own translation, not an official one.

In the Diesel COA, the report uses commas instead of decimal points (12,28 instead of 12.28). This is common on European lab reports, and it is worth noting.

The dates are written as day/month/year. The Diesel COA shows '03/04/2026' as the date received, which is 3rd April, not 4th March. This would seem normal to UK readers, but anyone used to US dates could misread it.

French, German and Spanish reports have the same traps.

A glossary table showing words used in an Italian CBD Flower certificate of analysis (COA) translated into English. NR appears in the COA’s key, but the results table uses '<LOQ' instead. We explain both in the cannabinoid table section. 

Who Tested the Flower, and Is the Lab Accredited?

Ambra srl, in Siena, Italy, tested the CBD flower in this guide. The COA is digitally signed by De Rossi Davide, and the producer is listed as the party that submitted the sample.

An accredited lab is one that has been assessed by an independent body for competence at specific tests. UKAS, the UK's national accreditation body, explains the difference between accreditation and certification, and lists the testing laboratories it accredits. ISO/IEC 17025 itself is an international standard, so the UK is just one example of where it's used. If you don’t see certificates on a COA, check the lab’s website or ask the seller. 

Which Batch Does the COA Cover?

The COA specifies its sample by report number and lot code. On this COA, the report number is 2026-1012/EXT/HPLC and the lot is DIES001K26. It also tells us when the sample was received for testing and when the report was issued. In this case, the sample was received on 3rd April 2026, and the report was issued on 14th April 2026. The results describe that one sample as it was when tested. They don't describe how any pack has been stored since.

The COA on each product page covers the current batch of a CBD flower and is updated when new batches arrive. If a COA has been updated since you made a purchase and you'd like a copy of the COA that applies to your flower, email us with your order number.

How Do You Read the Cannabinoid Table?

On the Diesel COA, the cannabinoid table has one row per compound. Reading left to right, you'll see the analyte (the compound measured, 'Analita'), the result ('Risultato'), the unit ('UM') and the measurement uncertainty ('Incertezza di misura'). This report gives results in % and mg/g.

Key terms found in the results:

• LOD is the limit of detection. This is the lowest amount the testing method can detect.

• LOQ is the limit of quantification. It is the lowest amount that the test can measure reliably.

• <LOQ means below the limit of quantification, an amount that the lab can't give a reliable number for. It doesn't mean zero, though.

• NR means not detected. It appears in the report's key, but the results table on this report uses <LOQ instead.

• %(m/m) is percentage by mass.

This is how to read the COA when looking at three rows:

A table showing some figures for 3 cannabinoids found on the Diesel COA report, translated into English

The table doesn't say anything about the effects of a CBD flower, and therefore doesn't make potency claims.

For a different layout, the Nebraska Department of Agriculture's guide to reading a hemp report is a US regulator's guide, so its columns won't match this Italian report.

What are Total CBD and Total THC on a COA?

Cannabinoids appear in two different forms: the acid form (CBDA, THCA) and the neutral form (CBD, THC). Heating changes the acid form into the neutral form, and the same process happens when you decarboxylate CBD flower.

COAs sometimes have a section for total THC and total CBD that combines the neutral form with the converted acid form. It's important to know the total amounts because some limits are often written around total THC, not just its neutral or acid form.

The Diesel COA states that total THC = THC + (THCA × 0.877) and total CBD = CBD + (CBDA × 0.877). The 0.877 factor adjusts for the acid form being heavier than the neutral form, so each unit of acid converts to slightly less of the neutral compound.

We can test this formula and check whether total CBD comes out as reported on the COA:

• CBD = 12.28%

• CBDA = 0.74%

• Total CBD = CBD + (CBDA × 0.877)

• Total CBD = 12.28 + (0.74 × 0.877)

• Total CBD = 12.28 + 0.65 (we have rounded 0.649 to 0.65)

• Total CBD = 12.93%

• This matches the 12.93% printed on the report as CBD TOTALE

A table that shows the different compounds found in an example CBD Flower COA and how they should be used to calculate total amounts of THC and CBD. It explains how to better make sense of a CBD flower COA. 

What Does the Moisture Figure Mean?

The Diesel COA lists "Umidità totale" (total moisture) as 12.87%. It shows how much of the sample's total weight is moisture. The report also says the results are given "tal quale", meaning "as received", which means they include the moisture.

CBD flower is dried after harvest, and some moisture remains. Looking at how much moisture is present matters because a freshly cut CBD flower would test lower for THC and CBD than the same flower once dried. Two reports can look different even if the flower is the same. A moisture figure alone doesn't tell you whether a flower is fresh, dry or well stored.

What Else Can a COA Include?

A fuller COA can include pesticide, heavy metal and microbial tests. Microbial tests look for things like bacteria, yeast and mould counts. These often cover many different compounds and have their own tables, limits and results. Not every COA must include them, though. The Diesel COA covers cannabinoids and moisture only.

Some COAs also list terpenes; they’re responsible for some of the aroma and flavours found in CBD flower.

COAs can also include residual solvents. However, these are mostly included with extracts, not flower, because solvents are used in some extraction processes.

If you want to see other tests, you can ask the seller whether separate reports exist. A COA that covers fewer tests doesn't mean that the product is bad or not.

For more on what a fuller report looks like, the New Jersey cannabis regulator's guide to reading a COA is a US state guide, so the test panels and limits it describes are American and differ from UK practice.

How Can You Check a COA Is Genuine?

You can look for signs that a COA is a real, complete lab document, but none of them confirms authenticity on its own. Check that the report names the laboratory with an address. In the Diesel CBD flower COA, the lab is Ambra srl, Siena, Italy. You can look the lab up independently using its own website or an official accreditation database.

Check whether the report carries a report number and a lot code. The Diesel CBD flower COA lists 2026-1012/EXT/HPLC and DIES001K26. If an ID is missing, discuss it with the seller.

Check that the dates on the COA run in the correct order. If a report shows that the sample was received after the report was issued, it is worth asking the seller why the dates don't appear to make sense.

Does the report name a signatory? In our example COA, we can see that it is signed digitally by De Rossi Davide.

Using the formulas discussed previously, you can check for yourself whether the total cannabinoid values add up.

If you are ever unsure about a COA, ask the seller for the original PDF, or contact the lab directly using details you found yourself, not the ones printed on the document you are checking.

Our simplified COA authentication checklist:

• Lab named with address 

• Report number and lot code 

• Dates in sequence 

• Named signatory 

• QR code 

• Totals match the formula 

• mg/g agrees with % 

• Full PDF, all pages

FAQs

What does <LOQ mean on a COA?

<LOQ means the amount found was below the limit of quantification, the lowest level the lab can measure reliably. It doesn't mean zero or "not detected". The compound may be present at a level too low to put a reliable number on.

What is the difference between CBD and CBDA on a COA?

CBDA is the acid form of CBD, and CBD is the neutral form. Decarboxylation, the process of heating, can convert CBDA to CBD.

Why does a COA show total THC?

Total THC is a combination of neutral THC and its acid form, THCA. Some limits are written around total THC rather than THC alone.

Is ISO 9001 the same as ISO/IEC 17025?

No. ISO 9001 certifies a company's quality management system, while ISO/IEC 17025 accredits a lab's competence for specific tests.

What Should You Know Before Buying CBD Flower?

Now that you know how to find and read a COA, you can apply this knowledge when you buy CBD flower. Before buying, check that a COA is linked to the product, that the product name on the COA matches the listing, and whether the lab and issue date are shown. These are things to look at, and they do not necessarily mean that a CBD flower will be good or bad.

A COA provides information about one sample from one batch. It doesn't say how a pack has been stored since the test was carried out, and some lab tests are limited in what they measure compared to others.

If anything seems unclear, such as a missing COA, a different batch from the one you received or the wrong product name, the seller can answer.

Anyone taking medication, who is pregnant or who is breastfeeding should consult their GP before using CBD products.

Our CBD flower collection has COA links on each CBD flower listing, and our customer service team is glad to help with any questions you have.

Conclusion 

A COA can tell us a lot about a CBD flower and also has it’s limitations. It is a good resource to use as part of your investigation to see if a CBD flower is worth considering. Here’s a recap of the key takeaways:

• Find the COA on the product page, or ask the seller.

• Check the lab and the date.

• Check the report and lot IDs.

• Read the cannabinoid table. Results are in % and mg/g, and <LOQ doesn't mean zero.

• Check the total cannabinoid amounts (total THC and total CBD).

• Note the moisture figure.

• Note what the report doesn't cover.

• Ask the seller if anything is unclear.