Navigating GACP Documentation for Licensed Cannabis Farms in Thailand

Most GACP guidance for Thai cultivators concentrates on the parts of the standard an auditor sees on the day — soil, water, pesticide records, worker hygiene, post-harvest handling. Those are the parts that get fixed the week before an inspection. The part that cannot be fixed the week before is the one that starts earliest: where the genetics came from, and whether you can prove it.

This article is about that specific file. For the legal framework it sits inside — the instruments, their dates, and what is required of flower rather than of paperwork — see cannabis seeds and the law in Thailand, which is the page we keep current on regulation.

What GACP is, in one paragraph

GACP — Good Agricultural and Collection Practices — is the cultivation standard certified in Thailand by the Department of Thai Traditional and Alternative Medicine, part of the Ministry of Public Health. Certification follows an audit, runs for one to three years, and carries annual surveillance. Since the Notification on Controlled Herbs (Cannabis) B.E. 2568 took effect on 26 June 2025, cannabis flower that is sold or exported must come from a GACP-certified cultivation site. That is what turned GACP from a quality badge into a commercial precondition.

It is also a narrow gate, though a widening one. Industry reporting of DTAM’s figures puts the number of GACP-certified farms in Thailand at roughly 149 in late 2025, 217 by 13 February 2026 and 266 by 10 June 2026 — against more than 11,800 licensed operators, which even at the June figure is little more than two per cent. The trajectory matters as much as the number: uptake is steady, and certification remains a genuine differentiator rather than a formality. These counts come from trade reporting rather than a register DTAM publishes, so treat them as indicative and confirm the current position with DTAM if a decision turns on it.

Why the file starts at the seed

GACP is built on traceability: the ability to take any gram of finished material and follow it backwards to a specific plant, a specific batch, and a specific origin. That chain has a first link, and the first link is propagation material.

An auditor working backwards from a harvest lot will ask, in roughly this order:

1. Which plants produced this lot, and how were they identified?
2. Where did those plants come from — seed or cutting?
3. If seed: which variety, from which supplier, purchased when, under what batch or lot reference?
4. What evidence do you hold that the variety is what it is claimed to be?
5. Who handled the material between arrival and planting, and what does the record show?

A farm that answers the first two and shrugs at the third has a traceability break at the origin. It does not usually fail an audit outright, but it is the finding that reappears at every surveillance visit and it is the one that matters most to an export buyer, because it is the link that establishes what the plant actually is.

The records to keep, from packet to harvest

The standard does not prescribe a form. What it requires is that the chain is unbroken and legible to someone who was not there. In practice that means six records, each referencing the next:

1. Procurement record. Supplier name and address, purchase date, invoice or order reference, variety name, quantity of seed, and the batch or lot reference on the packaging. Keep the invoice; keep the packaging.

2. Goods-in record. Date of receipt, condition on arrival, who received it, where it was stored, and under what conditions. Seed viability is a storage question as much as a genetics one — we cover storage separately — and an auditor who sees a temperature-logged seed store forms a very different impression from one who finds a packet in a desk drawer.

3. Germination record. Date sown, method, quantity sown from which batch, quantity germinated, and the resulting seedling identifiers. This is the record that ties an anonymous packet to numbered plants.

4. Plant register. Every plant carries a unique identifier that traces back to its germination batch. If you take cuttings, the mother’s identifier propagates to them.

5. Cultivation log. Location, dates, inputs, interventions — the part of GACP everyone already knows about — keyed to the plant identifiers rather than to the field generally.

6. Harvest and post-harvest record. Which plant identifiers went into which harvest lot, on what date, and what happened to that lot afterwards.

Six records, each one pointing at the next, is the whole of traceability. The frequent failure is not that a farm lacks records; it is that the records exist in six systems that do not reference each other, so no one can walk the chain end to end.

What an auditor is actually testing

Two things, and it is worth being clear about the difference.

Identity — is this variety what you say it is? This is answered by provenance: a named breeder, a documented crossing, a purchase from a supplier who can be identified and contacted, and packaging that arrived sealed.

Consistency — will the next crop be the same as this one? This is answered by genetic stability. It is the reason feminised seed from a stable line is easier to defend than seed of unknown parentage, and the reason a farm that keeps mothers must document the mother’s own origin.

Neither question is answered by a laboratory report on the finished flower. Cannabinoid testing tells you what the crop contained; it does not tell you what the plant was or where it came from. Both belong in the file, and they are not substitutes for one another.

Sourcing seed that does not create a gap

The practical question for a licensed grower is what to look for in a seed supplier. Four things:

• A named, identifiable breeder. Dutch Passion has bred cannabis in Amsterdam since 1987, and every variety in this catalogue lists its parentage — Durban Poison as Durban crossed with an unknown indica, Critical Orange Punch as Critical crossed with Grandaddy Purps × Orange Bud, Siam’s Smile as a 1972 Thai jungle sativa crossed with Chocolate Thai. A documented crossing is the beginning of an identity record.
• Sealed, labelled packaging that survives to the audit. Do not discard it. It is evidence.
• A supplier who will put things in writing. A verbal assurance is worth nothing in a file.
• A domestic supply chain. Seed that crosses a border adds an import question to your provenance question. Dutch Passion Thailand delivers inside Thailand only, which keeps the chain of custody short and domestic.

The documentation we prepare

We supply provenance documentation to licensed growers. Because auditors and licence conditions differ, we do not publish a fixed pack and hand out the same thing to everyone — that produces documents that satisfy nobody.

Tell us what your licence or your auditor requires when you place the order, and we will prepare it alongside the shipment. It is considerably easier to assemble at the point of sale than to reconstruct six months later when an inspection is booked. A dated commercial invoice naming the varieties and quantities, the identity of the breeder and the supplier, and the sealed packaging in which the seed arrived are all inherent in an ordinary order — the value of asking in advance is getting them in the form your auditor wants to see.

What we will not do is issue a document that asserts something we cannot stand behind. We cannot certify your site, we cannot pre-empt DTAM’s judgement on your file, and we will not produce a cannabinoid figure for a crop we have not grown. A supplier willing to sign anything is a liability in an audit, not an asset.

Ordering and wholesale questions are answered in our FAQ; for documentation specifically, contact us with your licence details and your auditor’s requirements.

Choosing varieties for a certified operation

Two considerations beyond the usual ones:

Uniformity is a compliance property, not just an agronomic one. A crop that finishes together, tests consistently and looks alike across the block is far easier to lot and document than one that ripens over three weeks. Feminised seed from a stable line is the straightforward route to that.

Match the genetics to the certified site’s real conditions. A GACP site in Thailand is subject to the same heat and humidity as everyone else’s, and a variety that fails to structural mould in the wet season fails the whole lot, documentation or not. The varieties with open structure and shorter flowering times — Durban Poison, Power Plant, Frisian Dew, Siam’s Smile — are the ones bred for that. We go into the reasoning in preventing mould and bud rot in tropical Thailand and high-THC strains for outdoor growing in Thailand.

For low-THC production, where the compliance profile is different again, see high-CBD strains in Thailand.

A note on what this article is

This is a practical account of documentation, written by a seed supplier who is asked for it regularly. It is not legal advice and it is not a substitute for the certification body. DTAM publishes the standard and conducts the audits; where a decision turns on the requirement, confirm it with them or with your certifier. Thai cannabis regulation has changed materially three times since 2022 and will change again — the regulation page on this site is the one we re-date when it does.