ISPM 15 Stamp: Why Missing Wood Pallet Marks Delay Your Shipment

Your product passed inspection. Your documents are complete. But your shipment is stuck at the port.

The reason: a missing stamp on your wooden pallet.

This guide explains what the ISPM 15 stamp is, why it matters, and how to make sure your wood packaging doesn't hold up your cargo.

What is the ISPM 15 stamp on wood pallets?

The ISPM 15 stamp is an internationally recognized mark that proves wood packaging has been treated to eliminate pests. It applies to pallets, crates, and dunnage made from raw wood thicker than 6mm.

According to the International Plant Protection Convention (IPPC), this standard prevents insects and diseases from spreading across borders through untreated timber. Over 180 countries enforce ISPM 15 requirements, including the United States, European Union, China, Australia, and South Korea.

The stamp includes several elements:

• IPPC symbol: A wheat-shaped logo indicating compliance

• Country code: Two-letter ISO code (e.g., KR for Korea, US for United States)

• Producer number: Unique ID assigned to the treatment facility

• Treatment code: HT (heat treatment) or MB (methyl bromide fumigation)

The most common treatment is heat treatment (HT). According to IPPC guidelines, wood must reach a core temperature of 56°C for at least 30 minutes to be compliant.

What happens if your pallet has no ISPM 15 stamp?

Without the stamp, your shipment will not clear customs. The destination country treats unmarked wood packaging as a biosecurity risk. Customs authorities can hold, treat, or reject your cargo entirely.

Here's what non-compliance typically costs:

• Port fumigation: Emergency treatment fees plus several days of delay

• Detention fees: $100 to $300 per day while your container waits, sometimes higher depending on the port

• Rejection or destruction: $5,000 to $10,000 in penalties and reshipment costs

According to the U.S. Department of Agriculture (USDA APHIS), shipments containing non-compliant wood packaging "will not be allowed to enter the country" and may be re-exported or destroyed at the importer's expense.

In Australia, non-compliant timber packaging is "sent for treatment, export or destruction at the importer's expense," according to the Department of Agriculture, Fisheries and Forestry (DAFF).

Why do most first-time importers miss this?

The stamp is easy to overlook. It's about the size of a credit card, printed or branded directly onto the wood. If you've never imported goods on wooden pallets before, you may not know to check for it.

Many importers assume that if the supplier ships the goods, the packaging must be compliant. That's not always true.

According to USDA APHIS, "as an importer, you must ensure that all wood packaging material entering or transiting the United States is pest-free, debarked, heat-treated or fumigated, and marked with an ISPM 15 logo."

The responsibility falls on you, not the supplier.

How do you verify ISPM 15 compliance before shipping?

Before your shipment leaves the origin country, confirm two things with your supplier:

• Are the pallets and crates ISPM 15 certified?

• Is the HT or MB stamp clearly visible on the wood?

Ask for a photo of the stamp. The mark should be legible, permanent (stamped or branded, not a sticker), and visible on at least two sides of the pallet.

If your supplier cannot confirm compliance, request treated pallets or switch to exempt materials.

What packaging is exempt from ISPM 15?

Not all wood packaging requires treatment. According to the IPPC, the following materials are exempt because they are processed in ways that eliminate pest risks:

• Plywood

• Particle board

• Oriented strand board (OSB)

• Veneer

• Wood thinner than 6mm

• Pressed wood pallets (made from wood chips and adhesive under heat and pressure)

• Plastic pallets

If your shipments frequently use wood packaging, switching to plywood or pressed wood pallets can eliminate ISPM 15 concerns entirely.

How long is the ISPM 15 treatment valid?

Once wood packaging is treated and stamped, the certification does not expire. According to the IPPC, "a unit of wood packaging material that has been treated and marked in accordance with the ISPM 15 standard and that has not been repaired, remanufactured or otherwise altered does not require re-treatment."

However, if fumigation is used instead of heat treatment, the fumigation certificate is typically valid for 14 to 21 days. If your shipment is delayed beyond this window, you may need to fumigate again.

Heat-treated pallets (HT stamp) are more practical for most shipments because they have no expiration and are widely accepted.

Quick checklist: Avoiding ISPM 15 delays

• Ask your supplier if pallets are ISPM 15 certified before production

• Request a photo of the HT stamp on the wood packaging

• Verify the stamp includes: IPPC logo, country code, facility number, and treatment code

• For recurring shipments, consider switching to plywood or plastic pallets

• If using fumigation, confirm the certificate is valid at the time of arrival

• Include ISPM 15 compliance as a line item in your purchase contract

One missing stamp can cost you days at the port and thousands in fees. Check before you ship.