What changes for Canadian-sourced products on 19 August
On 23 July the US published 3 proclamations under Section 338 of the Tariff Act of 1930. Together they add a 50% duty to 554 tariff lines of Canadian origin, for goods entered from 12:01 am Eastern time on 19 August 2026. I've read the proclamations and their annexes so you don't have to; this note is what I'd want to know if I were importing from Canada.
The 4 facts that matter
- It is 50 percentage points on top of your current rate, in addition to whatever you pay today, and existing duties, fees and any anti-dumping measures continue to apply.
- USMCA does not help. The proclamations apply the duty whether or not the goods qualify under the trade agreement. If your Canadian products currently enter duty-free under USMCA, this is the first duty they will have carried in years.
- The scope is 3 lists: alcoholic beverages (beer, wine, cider, spirits), dairy inputs (milk powders, whey, casein), and a general list of 439 lines that runs from honey and garden seeds to furniture, paper, sports equipment and motorcycles.
- There are real exemptions. Goods already covered by Section 232 duties (most steel, aluminium and vehicle lines), energy, potash, fish, certain critical minerals, civil-aircraft articles and personal baggage are out of scope.
The deadline is customs entry, not despatch
All 3 proclamations use the same formula: the duty applies to goods entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. eastern time on 19 August 2026. Two things follow from that wording, and both catch people out.
- There is no exception for goods already in transit. I have read all 3 proclamations and none of them contains one. A shipment that leaves Canada on the 17th and clears customs on the 20th carries the duty. If CBP publishes transit relief later that would change it, but nothing published so far does, so the safe assumption is that only the entry date counts.
- Goods already in the US are not automatically clear. Withdrawal from a bonded warehouse for consumption is treated the same as entry, so stock sitting in a warehouse today and withdrawn after the 19th picks up the duty on withdrawal.
So the date to work backwards from is the one your customs entry is filed, not the one your pallet leaves on. For sea freight that lead time has largely gone already. For road freight from Canada it is days rather than weeks, and it is worth asking your broker for the specific date rather than assuming.
What it does to a landed cost
The arithmetic is blunt. A product with a $10 unit cost picks up an extra $5.00 of duty at the border. If it sells for $25, that is 20 points of margin gone in one entry date. Products with thin margins and Canadian origin are the ones to check first.
What I would do this week
- List your variants with Canadian country of origin and find their HS codes - in Shopify both live under Products > variant > Shipping > Customs information.
- Check each code against the lists. There is a free checker on the front page - it takes 6, 8 or 10 digit codes and tells you which list a line sits on. If you would rather start from the category than the code, there is a reading of which everyday products are on the lists and which are not.
- For anything on a list, work out the new landed cost and decide before 19 August whether the answer is a price change, a supplier conversation, or absorbing it knowingly. An unconscious 50 points is the only wrong option.
- Ask whoever files your entries for the last date a shipment can realistically clear before the 19th, and check what is already in transit or sitting in a bonded warehouse. Those are the units where the decision is still open.
- Remember the exemption check: if your line is already under Section 232, this particular action does not stack on it.
If you'd rather not do this by hand, this is the job Duty Diligence does: it reads the cost, HS code and origin you already keep in Shopify, shows the effective duty and landed margin per variant, and flags what changed when the rates move on the 19th. The snapshot is free and needs no card.
Sources: Federal Register documents 2026-14991 (alcoholic beverages), 2026-14992 (dairy) and 2026-14997 (general goods), published 23 July 2026; new HTS headings 9903.03.12-9903.03.16 and U.S. note 51 to subchapter III of chapter 99. The checker lists were machine-read from the scanned annexes - verify against the source before acting on any single line. Informational, not customs, legal or financial advice.