Source: Supply Chain Dive
Date: 15th August 2025

New Rule Aligns Postal Service Standards with Universal Postal Union Customs Regulations.

Beginning September 1, the U.S. Postal Service will require all international commercial shipments to include a six-digit Harmonized System (HS) code on their customs declaration forms.

The HS system, developed by the World Customs Organization, is used globally to classify goods and assess tariffs. This update aligns U.S. mailing standards with the Universal Postal Union’s new regulations, which require the use of HS codes for commercial goods in member countries.

The Postal Service, along with international shipping providers, has provided tools to help shippers comply with the requirement.

However, a clear and accurate product description is essential to applying the correct HS code. Shipments sent without an HS code risk rejection by customs officials in the destination country or the imposition of incorrect duties.

The requirement underscores the growing importance of accurate customs data in ensuring the smooth operation of international trade, particularly as e-commerce volumes continue to rise.

This change comes just days after another major policy shift for international postal shipments. Effective August 29, U.S.-bound postal packages will be subject to either International Emergency Economic Powers Act (IEEPA) tariffs or a flat $80–$200 duty, marking the end of the long-standing de minimis exemption.

Together, these regulatory changes significantly reshape the cost structure and compliance requirements for global shippers using postal networks.

Logistics and supply chain implications of the new HS code requirement for U.S. Postal Service international shipments:

• Customs Clearance and Compliance
  Requiring a six-digit HS code ensures standardised classification of goods but raises the risk of customs clearance delays if codes are missing or incorrect. Inaccurate codes may lead to shipments being held, rejected, or assessed at higher duty rates. E-commerce sellers in particular must strengthen product cataloguing and code assignment to avoid penalties and rejections.
• Increased Costs for Shippers
  Accurate HS code assignment adds administrative costs, especially for businesses managing large catalogues. Non-compliance could result in higher duties, fines, or returns. Combined with the Aug. 29 IEEPA duty requirement ($80–$200 per shipment or tariff-based duty), landed costs will rise significantly, particularly for small and medium exporters.
• Impact on E-commerce and SMEs
  High-volume e-commerce sellers must now ensure every SKU has a correct HS code, increasing complexity. Smaller businesses without digital tools may face higher rejection rates or added costs to stay compliant. Larger platforms and logistics providers with automated HS code databases are better positioned to adapt.

The HS code requirement will raise compliance costs and operational challenges in the short term, but over time, it should create more predictable and efficient customs processing worldwide.