Short answer: For years, tariff planning for Shopify brands meant tracking Section 301, Section 232, and the occasional trade remedy case. In 2026, a new authority joined the stack: tariffs imposed under the International Emergency Economic Powers Act (IEEPA). These duties layer on top of existing Section 301 rates, they move on a faster political timeline, and they target different policy goals. If your landed-cost model still only tracks the old authorities, it is understating what you owe. Here is what changed and what to watch.
What the IEEPA tariffs are
IEEPA gives the President broad authority to regulate commerce during a declared national emergency, and in 2026 that authority was used to impose additional duties on imports tied to specific emergency declarations. Unlike Section 301, which follows a USTR investigation and a public comment process, IEEPA actions can move quickly and cover broad categories of goods.
The practical difference for importers is speed and breadth. Section 301 changes arrive with months of notice and detailed product lists. IEEPA actions can arrive with weeks of notice and broader product coverage. Your planning horizon for IEEPA-exposed categories has to be shorter and your monitoring tighter.
How IEEPA duties stack with Section 301
The duties add up. A product already paying 25 percent under Section 301 that gets hit with an additional IEEPA duty pays both, applied to the customs value in sequence. This stacking is where brands get surprised: the landed-cost model built last year assumed one layer, and the invoice shows two.
Work through your top SKUs and compute the stacked rate explicitly. For each product, list every applicable duty (MFN rate, Section 301, Section 232 if steel or aluminum is involved, IEEPA, plus any AD/CVD) and the total. Most brands have never seen the full stack written down in one place, and the total is usually higher than the number anyone quotes in meetings.
Exemptions, exclusions, and the moving target
IEEPA actions have included exemption mechanisms, but they work differently from Section 301 exclusions. The timelines are compressed, the criteria are political as much as technical, and the exemption lists change as the underlying emergency declarations evolve. Do not assume the Section 301 exclusion playbook transfers directly.
Track the Federal Register notices for each IEEPA action separately from your Section 301 tracking. They are different dockets, different comment periods, and different exemption processes. Brands that lump all tariff monitoring into one feed miss the IEEPA-specific deadlines, which tend to be shorter.
What to do this quarter
First, update the landed-cost model: add an IEEPA column to every SKU's duty stack and recompute margins. Second, review your supplier contracts for duty-change clauses; IEEPA's speed makes shared-cost provisions more valuable than they were under the slower Section 301 cadence. Third, talk to your broker specifically about IEEPA classification: the product scope descriptions differ from Section 301 lists, and misclassification under a new authority is the easiest mistake to make.
Fourth, scenario-plan. IEEPA duties are more reversible than Section 301 duties because they tie to emergency declarations, which means they can also expand quickly. Model three cases for 2027 planning: IEEPA holds at current levels, IEEPA expands to new categories, IEEPA rolls back. The brands that modeled all three will move fastest whichever happens.
The bigger lesson
IEEPA's arrival is a reminder that the tariff landscape now changes on political timelines, not trade timelines. The monitoring muscle most brands built for Section 301 (quarterly reviews, annual planning) is too slow for authorities that move in weeks. The fix is not anxiety; it is cadence. Monthly tariff reviews, a duty stack per SKU that someone owns, and a broker relationship where new authorities get flagged proactively.
The brands handling 2026 well are not the ones that predicted IEEPA. They are the ones whose systems absorbed a new duty layer without panic: the model updated, the contracts flexed, the monitoring caught the notices. Build for absorption, not prediction.
Do IEEPA tariffs apply to goods already on the water?
Generally, the effective date in the implementing notice controls, and goods entered after that date pay the duty regardless of when they shipped. Check the specific notice: some actions have carve-outs for goods in transit, most do not.
Can IEEPA duties be challenged in court?
Challenges have been filed questioning the scope of IEEPA tariff authority, and litigation is ongoing. Do not plan around a favorable ruling; pay the duties as assessed and preserve your rights through proper protest procedures in case the legal landscape shifts.
How are IEEPA tariffs different from reciprocal tariffs?
They are different legal authorities that can apply simultaneously. Reciprocal tariff actions have their own product lists and rates. Your SKU-level duty stack needs a line for each authority; conflating them is how underpayments happen.