With trade talks regarding the World Trade Organization and North American Free Trade Agreement under way, the Trump administration can help American exporters, especially small businesses, by urging other countries to relax a barrier on small trades.

The de minimis threshold is a valuation ceiling governments set on imported goods. Shipments costing over that amount are subject to duties, taxes and clearance procedures. The U.S. has one of the highest thresholds in the world, at $800, which is beneficial to American consumers...