@syntaxseed I feel like I understand this for goods purchased by big companies and imported into shipping ports, but for consumer goods ordered directly from Canada, I wonder how it's handled?
In Ireland, if I buy something from the UK, the post office (An Post) sends me a VAT invoice that I must pay before they will deliver. I wonder, would USPS/UPS/FedEx/etc. have to do the same under a US tariff against Canada and Mexico?