US begins collecting new tariffs amid major shifts in global trade norms

.S. customs agents have started collecting President Donald Trump’s new unilateral 10% tariff on imports from many countries, marking a dramatic departure from the post–World War II system of mutually agreed tariff rates.

The baseline tariff took effect at 12:01 a.m. ET on Saturday at U.S. seaports, airports, and customs warehouses, with higher reciprocal tariffs on goods from 57 major trading partners scheduled to begin next week.

“This is the single biggest trade action of our lifetime,” said Kelly Ann Shaw, a trade lawyer at Hogan Lovells and former White House trade adviser during Trump’s first term. Speaking at a Brookings Institution event on Thursday, Shaw noted that while the tariffs are expected to evolve as countries negotiate lower rates, they represent a seismic shift in the global trading system.

Trump’s announcement on Wednesday sent shockwaves through global markets, wiping out $5 trillion in market value for S&P 500 companies by Friday’s close—a record two-day decline. Oil and commodity prices plummeted, prompting investors to seek refuge in government bonds.

Among the countries first impacted by the 10% tariff are Australia, Britain, Colombia, Argentina, Egypt, and Saudi Arabia. U.S. Customs and Border Protection (CBP) has indicated that cargoes on the water at midnight Saturday will not benefit from a grace period; however, a 51-day grace period has been granted for cargoes loaded onto vessels or planes and in transit to the U.S. before the tariff took effect, provided they arrive by 12:01 a.m. ET on May 27.

At the same time on Wednesday, higher “reciprocal” tariff rates ranging from 11% to 50% were set to take effect. The measures include a 20% tariff on European Union imports and a 34% tariff on Chinese goods, which raises the total new tariffs on China to 54%. Vietnam is slated to face a 46% tariff, with discussions already underway between its officials and Trump’s administration. Meanwhile, Canada and Mexico remain exempt from the latest duties, as they are still subject to a separate 25% tariff linked to the U.S. fentanyl crisis for non-compliant goods under the U.S.-Mexico-Canada rules of origin.

The administration has also released a list of more than 1,000 product categories, valued at $645 billion in 2024 imports, that are exempt from the tariffs. These categories include crude oil, petroleum products, pharmaceuticals, uranium, titanium, lumber, semiconductors, and copper. Beyond energy, the Trump administration is reportedly investigating several of these sectors for additional national security tariffs.

As the new tariffs begin to reshape international trade, global markets and governments brace for the economic ripple effects of what many see as a bold and unprecedented move by the U.S. administration.

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