I thought it was more the case that shippers are asking the exporter to pay up front (and pass the prices along as they see fit) to limit the risk that the customer refuses to pay customs duties and rejects the package delivery, causing it to sit taking up valuable space in the shippers' warehouses.

> "Tarrifs" are paid by the importer. [...] These are being charged to the exporter

Ultimately, that's always the case.

But just like VAT or sales taxes are usually paid by the seller on behalf of the buyer, so could customs duties be levied by the exporter.