The U.S. secondhand fashion marketplace Poshmark has announced that, effective October 19, 2026, sellers will bear the full $50 penalty themselves for any package deemed by the United States Postal Service (USPS) to have non-compliant hazardous materials information. This adjustment means the platform's cost-sharing protection mechanism, which lasted only three months, is being completely terminated.

Key Points

  • Poshmark will end its subsidy for USPS hazmat fines on October 19; sellers previously bore only $5, but will now bear the full $50.
  • Since July 12, USPS has charged a $50 penalty for missing or non-compliant hazardous materials labeling on commercial packages; Poshmark previously covered the full amount and then the $45 difference.
  • A common trigger for the fine is sellers reusing boxes that bear old hazardous materials markings; it is recommended to thoroughly remove or cover such markings before shipping.

The mechanism lasted only three months. On July 12 of this year, USPS formally introduced this new charge for commercial packages. Any package involving missing hazardous materials information, non-compliant labeling, or common resale items such as perfume, nail polish, aerosols, and electronics containing lithium batteries that are not declared and packaged in accordance with regulations may be subject to the $50 fine.

According to market observations, platforms' initial responses to this charge varied. After the fine was introduced, eBay and Etsy offered no similar subsidy protection; Poshmark first absorbed the full $50 itself, then from August 1 changed to sellers bearing $5 while the platform subsidized the remaining $45, while reserving the right to increase the seller's share. Mercari, which also adopted partial sharing, has since September 1 had sellers and the platform each pay $25, with the corresponding portion deducted from seller income.

Poshmark's statement did not explain the specific reason for ending the $45 subsidy, instead focusing on sellers' preventive measures. Among these, reusing old boxes is a major source of packages being flagged by the system, especially common with boxes bearing the black-and-white diamond "Limited Quantity" marking—such markings are often seen on packaging for beauty products, aerosols, and cleaning supplies. Even if the newly packed items are not themselves regulated hazardous materials, the old corresponding marking may still cause the package to be treated as hazardous materials as a whole. The platform therefore requires sellers to thoroughly remove or cover such markings before shipping to avoid this high fee.

This adjustment highlights the compliance pressure facing secondhand trading platforms amid the rapid growth of categories such as secondhand beauty and electronics: on the one hand, platforms need to balance user retention and assessment risk through cost-sharing designs; on the other hand, neglect in the packaging reuse process can easily trigger high USPS fines. With Poshmark shifting the full cost to sellers, another point of industry attention is whether Mercari, which still bears half the cost, will take the same step.

Source: Poshmark Ends USPS HAZMAT Fee Protection, Sellers Face Full $50 Charge · Originally published 2026-10-06