U.S. President Donald Trump reacts as he speaks with members of the media on the South Lawn before boarding Marine One at the White House, in Washington, D.C., U.S., Feb. 28, 2025.
Nathan Howard | Reuters
U.S. importers and their customers are about to experience the full force of President Donald Trump’s unprecedented use of emergency economic powers.
To that point, 25% tariffs on imports from America’s top two trading partners, Canada and Mexico, went into effect at midnight Tuesday, as did an additional 10% tariff on Chinese imports. Canadian energy will be tariffed at a lower rate of 10%, also as of midnight Tuesday.
It’s difficult to overstate how far-reaching the impact of these tariffs will be, or how quickly they will be felt.
U.S. trade with Mexico, Canada and China last year accounted for around 40% of America’s total commerce in goods around the world.
And unlike traditional trade policy, these tariffs are designed to deliver a financial sting right away, trade experts told CNBC.
“From a technical standpoint, the imposition of the tariffs is basically a light switch. They’re on or they’re off,” said Daniel Anthony, the president of Trade Partnership Worldwide, a policy research firm.
Literally overnight, the cost of importing, for example, $100,000 worth of limes from Mexico increased by $25,000 Tuesday. This is money that the importer will need to pay directly to U.S. Customs and Border Protection when the limes cross the border.
Target CEO Brian Cornell told investors Tuesday that shoppers could see produce prices rise within days, the result of tariffs on Mexican fruits and vegetables.
Even if a glitch prevented tariffs from being collected starting at exactly 12:01am Eastern Time Tuesday, they would still be tallied, and importers could expect to receive a tax bill retroactively, said Nicole Bivens Collinson, a Washington trade lobbyist and managing principal at Sandler, Travis & Rosenberg.
“It’s like when you get an Uber bill and you forgot to tip, and add it on later,” she said.

Along with the two new North American tariff rates, Trump also signed an order Monday doubling his earlier 10% tariff on imports from China, for a total 20% additional tariff rate on the nation.
Taken together, Canada, China and Mexico accounted for $2.2 trillion worth of U.S. overseas trade in 2024, according to federal census data. About $840 billion of that came from trade with Mexico, $762 billion from Canadian imports and exports and $582 billion from China.
Extraordinary power
Containers at the Port of Vancouver in Vancouver, British Columbia, Canada, Feb. 28, 2025.
Ethan Cairns/Bloomberg via Getty Images
Part of the reason Trump could do this so quickly is because the White House is invoking a sweeping national security law to justify the new levies.
Until now, the International Emergency Economic Powers Act, IEEPA, had been used mainly to impose emergency sanctions on foreign dictators or suspected terrorist groups.
But the Trump administration argues that the illicit global fentanyl trade and immigrants at the Mexican border both qualify as “unusual and extraordinary” foreign threats to American national security, justifying Trump’s use of emergency powers under IEEPA.
Trump is using the law in a broader way than any president has before, Trade Partnership Worldwide’s Anthony explained.
Trump is also inviting legal challenges, he said, by pushing the boundaries of presidential authority.

For now, consumers will bear the brunt of the tariffs in higher prices, experts say. The Tax Policy Center estimates that Trump’s Mexico and Canada tariffs alone will cost the average household an additional $930 a year by 2026.
The imposition of massive new tariffs on U.S. imports from Canada, China and Mexico are a sharp reminder of how much power Trump wields over global commerce.
But they also hint at the limitations of this power.
In the case of so-called de-minimis shipments, the Trump administration imposed new levies on millions of shipments entering the United States, before the federal government had the means to actually collect the fees.
The de minimis mess
Oscar Wong | Moment | Getty Images
So-called “de minimis” imports are international shipments valued at $800 or less. Historically, these low-value, person-to-person imports have been exempt from U.S. tariffs.
Several of the world’s biggest e-commerce companies take advantage of the de-minimis loophole by shipping their products directly to consumers from overseas.
Fast fashion sites, like Temu and Shein, ship goods directly from China to American consumers. They have helped fuel an explosion in U.S.-bound de-minimis shipments in recent years.
But collecting tariffs on de-minimis goods is harder than it looks.
“There’s a whole infrastructure system set up for normal shipments that come in to the country,” said Collinson, who previously served as a U.S. trade negotiator. But this system doesn’t exist for de-minimis imports, she added.
Last year alone, the U.S. accepted more than 1.3 billion overseas shipments that qualified for de-minimis tariff exemptions, according to federal data.
To process that many new shipments, the federal government will need to hire more customs agents, experts said.
Nonetheless, in early February Trump announced that the United States would begin collecting tariffs on low-value shipments from overseas.
Trump’s order gave the U.S. Postal Service mere days to implement a system to begin collecting tariffs on millions of small packages every day.
It also sowed chaos throughout the international postal system, culminating on Feb. 4 with an announcement that USPS had suspended all parcel delivery services from China and Hong Kong “until further notice.”
A day later, the postal service reversed course and resumed processing the de-minimis parcels. But it did not collect any tariffs on them.
Soon after, the Trump administration issued an amendment to the China order, formally delaying any effort to collect tariffs on de-minimis imports until “adequate systems are in place to fully and expediently process and collect tariff revenue” on them.
The U.S. Postal Service didn’t immediately respond to a request for comment.
A month later, the White House put similar de-minimis waivers in place Sunday for Canada and Mexico, ahead of imposing the new 25% tariffs.
It’s unclear when a de-minimis tariff collection system might be up and running.
A U.S. Customs and Border Protection spokeswoman told CNBC, “The dynamic nature of our mission, along with evolving threats and challenges, requires CBP to remain flexible and adapt quickly while ensuring seamless operations and mission resilience.”
But Anthony noted that the delay for China was “open ended.”
“Part of the challenge is [federal] personnel and bandwidth,” he said. Customs and Border Protection may not have the staff or resources available to handle the new volume of shipments and packages, he said.
Officials must also determine how the levy will be assessed and paid, and how customs officials will process tens of millions of new data points furnished by shippers for each individual package, the experts said.
“Anyone can develop a good policy, but whether that policy can actually be effectuated is critical,” Collinson said.