Here’s the alert the USPS issued on November 3, 2025:
“Starting November 15, 2025, the Postal Service will begin converting the material of the Priority Mail Envelope (EP14), Priority Mail Express Envelope (EP13C), and Milipac Priority Mail Envelope (MILIPAC) from Tyvek to poly (plastic). The envelope dimensions (11-5/8″ x 15”) will remain the same.
“Poly envelopes have been a trusted component of USPS packaging for more than 15 years, featured prominently in both our Standard Poly Padded and Expedited Packaging Supplies Programs. Throughout their use, they’ve consistently proven to be highly durable and reliable.
“This transition aligns with USPS’s sustainability goals, particularly our target to boost recycled content in packaging materials to 74%. Adopting poly packaging is a key step in achieving that objective.
“The transition will be phased, with full implementation anticipated by December 2025. Customers who prefer Tyvek envelopes are advised to order early, as existing inventory will be available only while supplies last. Once Tyvek stock is depleted, all orders will be fulfilled using poly envelopes.”
