Buyer's guide·4 min read·By the BestPack technical team·Published: Aug 30, 2026

How to Read the IPPC Stamp on a Pallet

The IPPC stamp is your pallet's passport: if it's wrong, your shipment doesn't cross the border. In 4 minutes you'll know how to read every part of the mark, where it has to be and how to spot an invalid stamp before customs does.

The 4 parts of the stamp

The ISPM 15 / NOM-144 mark is made up of four elements inside a border:

  • The IPPC wheat symbol: the logo of the International Plant Protection Convention. Without the wheat symbol, the mark is not valid.
  • Country code: two ISO letters. For packaging treated in Mexico: MX.
  • Registration number: the unique identifier of the manufacturer or supplier authorized by the plant health authority (in Mexico, issued through SEMARNAT/SENASICA). It lets you trace who treated that piece.
  • Treatment code: HT for heat treatment (the standard in Mexico) or MB for methyl bromide fumigation. It may be accompanied by DH when dielectric heating was used.

Where and how it must be marked

The mark must appear on at least two opposite sides of the pallet or packaging and must be legible, permanent and non-transferable (heat-branded or applied with durable paint/stencil — never an adhesive label or a hand-drawn mark). Red and orange must not be used, as those colors are reserved for dangerous goods labeling.

Signs of an invalid or suspicious stamp

  • Mark on only one side, blurred, incomplete or covered by paint.
  • No wheat symbol, no country code or no registration number.
  • A "generic" stamp that is identical on pallets from different origins (possible counterfeit).
  • Pallet re-nailed or repaired with new lumber WITHOUT re-certification: a repair with untreated wood voids compliance even if the original stamp is still visible.
  • Wood with bark, active bore holes or fresh sawdust: even if the stamp is valid, the condition can trigger a rejection.

Buyer's tip: ask your supplier for their registration number and compare it against the physical stamp on the pallets you receive. If they don't match, that pallet was not treated by whoever sold it to you.

Does the stamp expire?

The treatment does not "expire" over time: a treated and marked pallet remains valid as long as it is not repaired with untreated wood and the mark does not degrade. What inspectors do check is the current condition of the wood: active pests, bark or moisture can stop the shipment even if the stamp is legitimate.

Sources

  • FAO / IPPC — ISPM 15, Annex 2: The mark and its application.
  • SEMARNAT — NOM-144-SEMARNAT (marking of wood packaging in Mexico).

Frequently asked questions

What does HT mean on a pallet stamp?

HT (Heat Treatment) means the wood was heat-treated: 56 °C at the core for at least 30 minutes, in accordance with ISPM 15 / NOM-144. It is the standard treatment for export packaging in Mexico.

Is an adhesive label with the IPPC logo valid?

No. The mark must be permanent and non-transferable: branded with heat or applied with durable paint/stencil, on at least two opposite sides of the packaging.

Does the IPPC stamp expire?

The treatment does not expire, but compliance is lost if the piece is repaired with untreated wood or if the mark is no longer legible. Customs also evaluates the current condition of the wood (pests, bark, moisture).

Keep reading: NOM-144 Explained: Heat Treatment (HT) for Export Pallets in Mexico · What Is ISPM 15? Heat-Treated Pallets & Wood Packaging for Export · BestPack export pallets.

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Heat treatment (HT) compliant with NOM-144 and ISPM 15.

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