Rules of origin: the clause that decides your margin

A free trade agreement does not abolish tariffs on everything that crosses a border between the parties. It abolishes them on goods that originate in one of the parties. Everything turns on what "originate" means, and that is defined by the rules of origin.

Consider a machine assembled in Ukraine from a German engine, an Italian hydraulic system, Chinese electronics and Ukrainian steel and labour. Is it Ukrainian? The answer is not obvious and it is not a matter of opinion. It is determined by a rule written for that specific tariff heading.

The three ways a rule is usually written

Wholly obtained: grown, mined or born in the country. Straightforward for agriculture, irrelevant for manufacturing.

Change of tariff heading: the finished product must fall under a different classification from the imported inputs. The logic is that a real transformation has occurred if the thing is now classified as something else.

Value added threshold: non-originating materials must not exceed a stated percentage of the ex-works price. This is the one people get wrong, because it depends on your own cost structure — the same product can qualify from one factory and fail from another.

Cumulation, which is where it becomes useful

Under diagonal cumulation, materials from other countries in the same cumulation zone count as originating. Ukraine joining the pan-Euro-Mediterranean convention meant that an input from Turkey or Poland could count towards Ukrainian origin instead of against it. For a manufacturer sourcing across the region, that changes which suppliers are commercially viable.

The practical part

You must be able to prove it. Supplier declarations, bills of materials, cost breakdowns, kept for years and produced on demand. A customs authority conducting a retrospective verification can withdraw preference and assess duty on consignments cleared long ago. I keep origin files the way I keep tax records, and for the same reason.

The origin rule is the clause an importer learns most expensively: a shipment that reads the tariff correctly and calculates origin wrongly loses the preferential rate at the border, and the difference comes straight out of the margin. After living through that once, the first thing I ask a new supplier is not the price but the origin declaration. Profit is very often won or lost on that single line.