ISPM 15 is an international regulation that requires solid wood packaging, including pallets, crates, and dunnage, to be heat-treated or fumigated and stamped with an official mark before it can be used in cross-border shipments. Its purpose is to stop wood packaging from carrying insects and plant diseases from one country to another. If your wood packaging is not treated and marked correctly, customs can hold, re-export, or destroy your shipment at your expense.
It is one of the most common reasons otherwise-compliant shipments get stuck at the border, and for US manufacturers it became stricter in January 2026. This guide explains what the rule is, what it requires, what changed, and the simplest ways to avoid it.
What ISPM 15 Actually Is
ISPM 15 stands for International Standard for Phytosanitary Measures No. 15. “Phytosanitary” just means plant-health-related. The standard was created by the International Plant Protection Convention (IPPC), a body under the United Nations Food and Agriculture Organization, and it is now recognized across the more than 180 member countries of the IPPC, including every major trading nation: the US, the EU, China, India, Mexico, Canada, and Australia.
The problem it solves is straightforward. Untreated wood can harbor wood-boring insects and pests. When that wood travels the world as pallets and crates, it carries those pests into ecosystems that have no defense against them. ISPM 15 requires the wood to be treated so the pests are killed before the packaging ever ships.
Importantly, the rule applies only to solid wood. It does not apply to manufactured wood products or to non-wood packaging, which matters more than most exporters realize (see below).
What the Rule Requires
To be ISPM 15 compliant, solid wood packaging has to meet three conditions:
- Treatment. The wood must be heat-treated to a core temperature of 56°C (133°F) for at least 30 continuous minutes, or fumigated with methyl bromide. Heat treatment is by far the more common method.
- Debarking. The wood must be debarked before treatment.
- Marking. Once treated, the packaging must be stamped with the official IPPC mark by a certified facility. The mark shows the IPPC symbol, the country code, the treatment facility code, and the treatment method (“HT” for heat treatment, “MB” for methyl bromide).
One detail catches a lot of shippers: if a treated crate or pallet is repaired, altered, or reassembled, it has to be re-treated and re-marked. The original stamp does not carry over to modified packaging.
Methyl bromide is one of the two approved treatments, but it is being phased down globally on environmental grounds under an IPPC recommendation. In practice this means heat treatment is becoming the default path, and exporters who rely on fumigation should expect that option to keep narrowing.
What Changed in January 2026
For most of 2025, US enforcement of one specific marking detail was paused. From March through December 31, 2025, APHIS and CBP did not take action on shipments that were compliant except for a missing hyphen in the IPPC mark, the hyphen that separates the two-letter country code from the producer code (for example, US-000).
That grace period ended. Effective January 1, 2026, CBP resumed full enforcement of the hyphen requirement, with no soft-enforcement period. A mark missing that hyphen is now grounds for the same treatment as any other non-compliant packaging. If you export from the US or import into it, every IPPC mark in your supply chain needs to be checked against the current Annex 2 format.
This sits within a broader pattern of active enforcement. US Customs and Border Protection inspects wood packaging at ports of entry and issues an Emergency Action Notification whenever it finds a violation, and CBP publishes its agriculture enforcement figures on a public dashboard updated through the fiscal year. The practical takeaway for shippers is simple: wood-packaging compliance is being checked, not waved through, and the marking detail that became enforceable again in January 2026 is part of what inspectors are now looking for.
What Happens If You Get It Wrong
Non-compliant wood packaging does not simply get waved through with a warning. Depending on the violation and the country, customs can:
- Hold the shipment at the port of arrival for secondary inspection
- Require fumigation or remediation before release, at your cost
- Separate the wood packaging from the cargo where operationally possible, exporting the wood while holding the goods
- Order the entire shipment re-exported if corrective action isn’t feasible
- Destroy the non-compliant packaging under official supervision
Any one of these blows the delivery window and adds cost. For a manufacturer shipping high-value, time-sensitive equipment, a held shipment can also mean a customer’s project or production line waits, which is the kind of failure that costs more than the freight.
The Exemption Worth Knowing
Here is the part most exporters miss: ISPM 15 applies only to solid wood. Two categories sit outside it entirely.
- Manufactured wood products such as plywood, OSB, and particleboard are exempt, because the heat used to make them already kills pests. The exemption applies only when the entire package is built from exempt materials; a plywood crate with a solid-wood frame or skids still needs ISPM 15 treatment and marking on those solid-wood parts.
- Non-wood packaging such as corrugated and engineered corrugated crates falls completely outside the standard. No treatment, no fumigation, no IPPC mark required.
For companies that ship heavy or fragile goods in wood crates, this is a practical lever: moving from solid-wood crates to an engineered corrugated alternative removes the ISPM 15 treatment-and-marking burden from that part of the packaging altogether, while also cutting weight and freight cost. It is not the right answer for every load, but for many it is a simpler path than managing wood-treatment compliance shipment after shipment.
Frequently Asked Questions
Does ISPM 15 apply to domestic shipments?
No. ISPM 15 governs wood packaging used in international trade. Purely domestic shipments within the same country are not covered. However, if a customer might re-export your packaging, they may require ISPM 15 compliance anyway.
Do I need ISPM 15 for plastic or corrugated pallets and crates?
No. The standard applies only to solid wood. Plastic, metal, and corrugated packaging are outside its scope, and manufactured wood products like plywood and OSB are exempt.
What does the IPPC mark look like?
It includes the IPPC symbol (a stylized wheat stalk), a two-letter country code, the certified facility’s code, and a treatment code (HT for heat treatment or MB for methyl bromide). As of January 2026, US enforcement again requires the hyphen between the country code and the producer code.
Can I reuse an ISPM 15-marked pallet?
Yes, as long as the mark is intact and legible and the pallet has not been repaired or modified. If it has been repaired or rebuilt, it must be re-treated and re-marked before reuse in export.
Who is responsible for compliance, the shipper or the carrier?
Responsibility rests with the party introducing the wood packaging into the shipment, typically the shipper or exporter. Customs holds the shipment regardless of who sourced the pallet, so the cost and delay land on the cargo owner.
How do I avoid ISPM 15 problems entirely?
Three options: buy pre-certified heat-treated wood packaging from an accredited supplier; verify every mark (including the hyphen) before loading; or move to packaging that falls outside the standard, such as engineered corrugated crates, where the goods allow.
How Korpack Can Help
Korpack is an engineering-led packaging partner that works with manufacturers on exactly this kind of problem. For exporters weighing their options, Korpack’s packaging engineers can assess where certified wood packaging makes sense and where an engineered modular corrugated crate is the simpler path for heavy and fragile goods. Because corrugated sits outside ISPM 15, it removes the treatment-and-marking step while cutting weight and freight cost. Korpack supplies and fabricates these crates as an engineering-led packaging partner and can produce to spec within a couple of days.
ISPM 15 is not complicated once you know the rule. The mistakes that cost money come from not knowing it, or from assuming last year’s marks still pass this year’s inspection.
Korpack’s packaging engineers can review your export packaging, flag ISPM 15 exposure, and show you where an engineered corrugated alternative removes the treatment-and-marking burden while cutting weight and freight cost.
855.567.7225 | korpack.com
Korpack is a technologically advanced packaging materials, contract packaging, and automation supplier that approaches solutions with an engineering mindset and creative flexibility. Founded by a packaging engineer, Korpack serves growth-oriented manufacturers across North America from its Chicagoland headquarters. This guide is part of Korpack’s Industrial Insights series. It is provided for general information and is not legal or customs advice; confirm current requirements with APHIS, CBP, or a licensed customs broker.
