On 23 June 2026 the European Commission signed decision C(2026) 4135 final, the first revision of EU GMP Annex 19 since 2006. It comes into operation on 24 September 2026. Most Canadian Licensed Producers skimmed the summary, saw the words "parallel import", and filed it under someone else's problem.
Cannabis retention samples are portions of a released lot held back so the batch can be re-examined later. The Cannabis Regulations require a Canadian LP to retain part of the tested sample for at least one year after the last sale of any portion of that lot. Annex 19 sets a different clock: one year past the expiry date.
Two clocks, two sample sizes, two storage jurisdictions. That gap is where export batches become hard to defend, long after everyone has signed off on them.
Cannabis retention samples and reference samples are not the same thing
Annex 19 splits retained material into two categories, and the vocabulary matters more than it looks. A reference sample is material from a batch of starting material, packaging material or finished product, stored so it can be analysed if a question arises during the shelf life of that batch. A retention sample is a fully packaged unit, stored for identification: presentation, packaging, labelling, batch number, expiry date.
One answers whether the product still meets specification. The other answers whether this is what was released to the market. Different questions, different evidence.
The annex does allow the two to be treated as interchangeable where the finished product is presented identically, meaning both are fully packaged units. For a Canadian LP shipping bulk dried flower to an importer who repackages into pharmacy-ready units, that exception rarely applies. What leaves a Montreal facility in a bulk container is not what reaches the German pharmacy shelf.
Where Canadian and European vocabulary diverge
Health Canada does not use the reference and retention split at all. Section 92 of the Cannabis Regulations refers to a representative sample and a retained portion of it, and stops there. So when your SOP says "retention sample" and your importer's quality agreement says "reference sample", the two documents are probably not describing the same material, the same quantity, or the same storage location.
Fix the vocabulary before you renegotiate the quantities. Agreements that use both terms loosely are the reason batch investigations stall on the first email.
What Health Canada requires under section 92
Section 92(1) of the Cannabis Regulations sets the base rule. Testing conducted under sections 90 to 91.1 must use validated methods on a representative sample of each lot or batch. The word doing the work is "representative". Material scraped from the top of one tote at the end of a packaging run does not represent a 40 kg lot, and a European auditor will ask how you drew it.
Section 92(2) sets the clock. A portion of that sample must be retained for at least one year after the date of the last sale of any portion of the lot or batch. Section 92(3) sets the size: the retained portion must be enough to determine whether the lot still meets the applicable requirements, and to determine the quantity or concentration of THC, THCA, CBD and CBDA.
Read 92(3) closely and you find its ceiling. It describes a quantity sufficient for one determination, not two. That is a floor, and Health Canada says as much in its good production practices guidance: licence holders may keep additional samples of a lot for their own purposes, to investigate quality complaints and decide whether a recall is warranted. Importers also look past the sample to the accreditation behind the method, which is why ISO/IEC 17025 shows up in almost every European quality agreement, and why buyers ask what an accredited test report actually proves.
The clock that starts too early
The Canadian clock runs from last sale, not from expiry. Sell a 40 kg export lot in a single shipment on 1 March and the Canadian retention obligation is satisfied on 1 March the following year. The same product can still be inside its shelf life in a European warehouse, with months left to run.
Your obligation ends. Your exposure does not. Destroy the retain on the Canadian schedule and the next importer complaint arrives with no Canadian counterpart to test against, which leaves you arguing about your own batch using someone else's data. A retained sample is also only as good as the record that ties it to a lot, which is where batch traceability earns its place. Retain to the European clock and the Canadian one takes care of itself.
What EU GMP Annex 19 requires after 24 September 2026
Annex 19 is a short document. Three numbers inside it decide whether your importer can defend your batch a year from now.
Start with the clock. Reference and retention samples from each batch of finished product are retained for at least one year after the expiry date. The reference sample sits in its finished primary packaging, or in packaging made of the same material as the marketed container.
Size comes next. A reference sample must be large enough to carry out the full analytical controls on at least two occasions, in line with the marketing authorisation file. Unopened packs should be used for each set where necessary.
Coverage is the third number. Where a batch is packaged in two or more distinct packaging operations, at least one retention sample comes from each of them.
The annex also expects the analytical materials and equipment needed to run every test in the specification to stay available, or readily obtainable, until one year after expiry of the last batch manufactured. Retiring an analytical method is a retention sample decision too, and almost nobody treats it as one.
Where the samples have to physically sit
Location is the part Canadian LPs get wrong. For finished product manufactured outside the EEA, Annex 19 offers two routes. Where an operational Mutual Recognition Agreement applies, reference samples may be taken and stored at the manufacturing site, covered by a written agreement with the importer or the site of batch release. Where no operational MRA applies, reference samples of the finished product must be taken and stored at an authorised manufacturer inside the EEA, preferably at the site where importation testing was performed.
Retention samples are simpler and stricter. They must be located within the EEA in every case, preferably at the site of the Qualified Person who certifies the batch. Even under an MRA, separate retention samples stay in Europe.
Now the part worth arguing about. The CETA GMP protocol's operational scope is built around medicinal products made by holders of a manufacturing authorisation or a drug establishment licence. A cultivation or processing licence issued under the Cannabis Act is neither of those things. Assume you are a section 7.2.2 supplier until your importer's Qualified Person confirms otherwise in writing. Budget for storage inside the EEA and be pleasantly surprised.
What the 2026 revision added
The new section covers parallel imported, distributed and traded products. Physical samples of the packaging materials used in re-packaging, meaning labels, cartons, patient information leaflets and other inserts, are kept for the shelf life of the re-packaged product. Reference samples of the re-packaged product are not required. A retention sample is taken for each re-packaging operation and held at least one year past the expiry date, showing both primary and secondary packaging.
Where a physical retention sample cannot reasonably be kept, and the competent authority has agreed in advance, a photographic or digital sample is now allowed, subject to the record integrity principles of Annex 11. If your flower moves through a parallel distributor after release, that leg of the chain now carries its own sample file. Ask your importer who holds it, and read it alongside the EU QP batch release duties that sit on top.
The four-gap retention sample check
Four questions, four documents. Run them before the next European shipment closes.
| Gap | Health Canada, section 92 | EU GMP Annex 19 | What to do |
|---|---|---|---|
| Retention clock | 1 year after last sale of any portion | 1 year after the expiry date | Retain to whichever date falls later |
| Sample size | Enough for one determination | Enough for two full sets of controls | Size for two, then add your own retain |
| Storage location | Canada, at your site | Retention samples inside the EEA | Name the EEA holder in the agreement |
| Sample identity | Portion of the tested sample | Fully packaged unit as released | Agree who pulls the packaged unit |
Most LPs stall on the second row. Sizing is where a retention programme quietly fails, because the number was set once by someone reading section 92(3) on its own, and nobody reopened it when the first European contract landed. Two full sets of controls across cannabinoids, terpenes, microbials, heavy metals and pesticide residues, plus water activity, is a real quantity of flower, withheld from a saleable lot, for years. That is a margin conversation wearing a quality costume, which is exactly why it keeps getting deferred.
The third row bites almost as often. If the Qualified Person assumed the MRA route and you assumed Europe was storing everything, nobody is storing anything. Write it into the quality agreement with a named site, a named clock and a named person. Sample custody is also the first thing to check when retesting on import returns different numbers than your release certificate.
AlphaLeaf is a Health Canada Licensed Producer in Montreal, growing indoor, hand-trimmed flower from refined genetics. We hold export authorisation under the Cannabis Act and keep the ISO/IEC 17025 tested batch data, full traceability records and retained sample quantities that European importers and their Qualified Persons expect from a Canadian supply partner.
If a European shipment is already scheduled, this decision is being made right now by whoever fills the retain jar at the end of the packaging run. Give them the European number instead of the Canadian one. Talk to our quality team about sample sizing before the batch closes. It costs less than the alternative.
Frequently Asked Questions
What is the difference between a cannabis reference sample and a retention sample?
A reference sample is stored so a batch can be analysed if a question arises during its shelf life. A retention sample is a fully packaged unit kept for identification, so packaging, labelling, batch number and expiry date can be checked as released. EU GMP Annex 19 treats them as interchangeable only where both are presented as identical fully packaged units.
How long must a Canadian Licensed Producer keep a cannabis retention sample?
Section 92(2) of the Cannabis Regulations requires a portion of the tested sample to be retained for at least one year after the last sale of any portion of the lot or batch. For an export lot sold in a single shipment, that clock can run out while the product is still inside its shelf life in Europe, so most exporters retain to the European date instead.
Do retention samples for EU-bound cannabis have to be stored in Europe?
Yes. Annex 19 requires retention samples to be located within the EEA in every case, preferably at the site of the Qualified Person certifying the batch. Reference samples may stay at the Canadian manufacturing site only where an operational Mutual Recognition Agreement applies and a written agreement covers the arrangement.
How large should a cannabis reference sample be?
Annex 19 requires enough material to carry out the full analytical controls on at least two separate occasions. Canada's section 92(3) only requires enough to confirm the lot meets its applicable requirements and to determine THC, THCA, CBD and CBDA content. Size the retain to the European requirement and the Canadian obligation is covered automatically.
What changed in EU GMP Annex 19 in 2026?
The European Commission revised Annex 19 by decision C(2026) 4135 final on 23 June 2026, in operation from 24 September 2026. It adds a section for parallel imported, distributed and traded products: no reference sample of the re-packaged product, one retention sample per re-packaging operation held a year past expiry, and a photographic or digital sample only where justified and agreed in advance with the competent authority.
