They can, the problem is that if you declare this as different parts then you will have to pay taxes accordingly to the chosen HSCode for each one in the declaration.

If you search for the HSCODE you will find that offshore oil and natural gas drilling and production platforms have their own, 8431434000, which means if you declare only this one you will pay no taxes.

▲ magicalhippo 3 days ago | parent [-]

In my experience they're also a bit particular about declaring things as they are on the border.

An oil platform getting towed into place is one piece, not an IKEA kit or similar.

That said, could very well be the local customs officer was just totally unprepared and this was the solution they came up with on the spot. I've seen other cases where different companies have gotten directly contradictory instructions from different customs offices on the exact same scenario.

	▲	Lovesong 3 days ago \| parent \| next [-]
		Yes, the final say is always on the particular custom where the goods will get the clearance, so they will call the shots on the way the procedure should be done. The IT system in place is just there to accommodate how customs should proceed, so if they have different ways to solve the problem, the customs officer will just find the one he's more used to. But you're right that if there's a HSCode for something built, furniture vs wood for example, then the more "accurate" should be used, as they will have different tariffs too.
	▲	dotancohen 3 days ago \| parent \| prev [-]
		`> An oil platform getting towed into place is one piece, not an IKEA kit or similar.` They could call it the Integrated Key Energy Anchor.