Now tariffs are imposed, my import cost per widget is $139. Not only do I have to jack up my US price to $189, I have to jack up my UK price to £142, meaning UK customers are also paying the tariff now.
Even if you’re a bit smarter about your logistics and use an FTZ or drawback against the import duties, imagine you sell two widgets, one where you don’t pay import duties (bound for the UK) and one where you do (remaining in the US). Your total cost to import is $239.
Instead of making your US customers eat all the cost of the tariff, you might instead adjust your retail prices to $170 and £128 respectively. Again, now your British customers are paying an increased price due to the tariffs.