Rules of Origin
The technical tests deciding where goods legally originate, written per tariff heading.
Goods wholly obtained in one country originate there. Anything made from materials of several origins is decided by the rule for its tariff heading: usually a change of HS classification at four or six digits, sometimes a minimum percentage of local value.
Preferential rules under a trade agreement differ from non-preferential ones, and are often stricter. Claiming preference means applying that agreement's rule, not asserting where the factory is.
Repackaging, labelling, simple assembly and dilution never confer origin, however much labour they involve.
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