Section 321

Section 321 refers to 19 CFR § 10.151 (and the underlying Section 321 of the Tariff Act of 1930), the regulatory provision that allows informal customs entry for low-value shipments. In practice, the term is commonly used interchangeably with 'de minimis,' though strictly speaking Section 321 is the administrative entry mechanism (simplified clearance via electronic manifest) while 'de minimis' refers to the underlying duty-free threshold ($800 as of 2024). For ecommerce operators, Section 321 entries have been the workhorse of direct-to-consumer cross-border commerce: each individual customer order qualifies as a separate Section 321 entry if under the threshold, and platforms like Shopify, the major customs brokers, and 3PLs have built the entire international-fulfillment infrastructure around the assumption that 90%+ of B2C shipments would clear under Section 321. The 2025–2026 policy changes affect Section 321 in two ways: (1) the de minimis dollar threshold is being effectively removed for shipments from specific countries (China and Hong Kong as of February 2025; potentially others), meaning Section 321 informal entries from those origins are no longer eligible regardless of value; (2) even where Section 321 remains available, additional reciprocal-tariff and product-specific Section 232/301 duties may apply, requiring full customs entry rather than the informal Section 321 path. For Shopify Plus merchants previously relying on Section 321 to keep landed costs low, the practical migration steps are: re-classify the SKU catalog with HS codes; enable a duty-and-tax calculation engine at checkout (Zonos, Avalara, or equivalent); decide on a duty-handling strategy (DDP: delivered duty paid by merchant, baked into price; or DDU: delivered duty unpaid by customer at the door); update margin floors to reflect the new duty stack on cross-border orders; and audit the existing fulfillment routes to determine which can stay direct-from-origin and which need to shift to a domestic warehouse buffer.