If you’re running a business that moves anything across a border, you’ve probably spent the last year glued to Truth Social or refreshing Federal Register updates. It’s been a wild ride. Honestly, keeping track of the start dates for these duties feels like trying to catch smoke with your bare hands. One day everything is "negotiable," and the next, a 10% tax is hitting your shipment from Helsinki.
People keep asking: when do us tariffs start? The answer isn't a single date. It’s a rolling calendar of "effective at 12:01 a.m." notices that began the moment Donald Trump took his second oath of office in January 2025.
We aren't just talking about China anymore. We're talking about Greenland, Canada, Mexico, and basically anyone with a trade surplus.
The 2026 Greenland Escalation
The latest bombshell dropped just hours ago. On Saturday, January 17, 2026, President Trump announced a brand new set of tariffs targeting European allies. This isn't about steel or cars—it's about Greenland.
Because countries like Denmark, France, and the UK sent troops for military exercises in Greenland, they’re getting hit. Here is the timeline you need to circle in red:
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- February 1, 2026: A 10% tariff kicks in for Denmark, Norway, Sweden, France, Germany, the UK, the Netherlands, and Finland.
- June 1, 2026: That rate jumps to 25% if a deal to purchase Greenland isn't reached.
It sounds like a movie plot. It isn't. If you’re importing German machinery or French wine, your costs just changed while you were sleeping.
What Happened in 2025? (The Foundation)
To understand what’s coming, you have to look at the wreckage of 2025. The administration didn't wait. They used the International Emergency Economic Powers Act (IEEPA) like a sledgehammer.
The first major wave hit in the spring. On April 5, 2025, a 10% "baseline" reciprocal tariff went live for almost everyone. A few days later, on April 9, that rate scaled up to 34% or even 50% for specific countries with huge trade deficits.
China, as usual, was the primary target. While the campaign talked about 60% across the board, the reality was a bit more nuanced—but still brutal. By October 2025, the effective tariff rate on Chinese goods was sitting at a staggering 37.4%.
The North American "Fentanyl" Tariffs
Canada and Mexico had a chaotic year. In February 2025, Trump threatened 25% tariffs on all imports unless "invasion" and drug flows stopped.
Things moved fast. By March 4, 2025, those tariffs actually started. But then, a twist: by March 6, the administration exempted goods that strictly followed USMCA (United States-Mexico-Canada Agreement) rules.
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Basically, if your product is "North American enough," you might be safe. But if it’s just transshipped from China through a Mexican port? You’re paying. As of early 2026, the rate for Canadian goods that don't meet USMCA rules sits around 35%.
Specific Sector Start Dates You Might Have Missed
Wait, there's more. The administration has been using Section 232 investigations to target specific industries. These aren't broad country taxes; they are "national security" strikes.
- Semiconductors: On January 14, 2026, a proclamation added a 25% duty to advanced AI chips. This went live January 15, 2026.
- Timber and Wood: New duties between 10% and 25% started on October 14, 2025.
- Heavy Trucks: Medium and heavy-duty vehicles faced new rates starting November 1, 2025.
The De Minimis Death Sentence
If you’re a small e-commerce seller using Shopify or Amazon, the biggest date for you was August 29, 2025.
That’s when the "de minimis" exemption died. Before that, you could ship packages under $800 into the US duty-free. Not anymore. Now, almost everything coming from China and Hong Kong gets hit with a 54% duty or a flat $100 fee per package if it comes through the mail.
It killed the "dropshipping from China" business model overnight.
Why the Dates Keep Shifting
You’ve probably noticed that some tariffs get announced and then... nothing happens for a while. That’s the "Negotiation Gap."
Take the massive reciprocal tariff hike on China. It was supposed to go even higher in late 2025, but a "deal" struck in November 1, 2025, paused the 24% increase. In exchange, China agreed to buy 12 million metric tons of soybeans.
Currently, that 10% reciprocal baseline for China is suspended until November 10, 2026.
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It’s a leverage game. The "start date" is often just a deadline for the other country to start buying American cows or corn. If they don't, the tax flips on like a light switch.
Actionable Steps for Shippers and Importers
The "when" matters, but the "how" is how you survive. If you are trying to figure out when do us tariffs start for your specific cargo, stop looking at the news and start looking at these three things:
- Check your HTSUS Codes: Tariffs are applied based on the Harmonized Tariff Schedule of the United States. If your classification is wrong, you might be paying a 25% "fentanyl" tax when you shouldn't be.
- Audit your Origin: "Made in Mexico" only works if you can prove it. The CBP is cracking down on transshipment. If you’re moving goods from China through a third country to dodge the 2025 start dates, expect a 40% "transshipment penalty" which went into effect on August 7, 2025.
- Watch the Federal Register: Forget Twitter for a second. The official start date is only real once it hits the Federal Register.
The reality is that we are in a "perpetual tariff" environment. The average effective tariff rate in the US has jumped from roughly 2% in early 2025 to over 18% today. This is the highest since the 1930s.
Keep your cash reserves liquid. These dates change with a single Truth Social post, and "effective immediately" means exactly that.
To stay ahead, you should immediately request a formal ruling from Customs and Border Protection (CBP) if you are unsure about your product's "Country of Origin." This is the only way to get a legally binding answer that prevents retroactive bills that could bankrupt your operation.