Classification is the part of this trade that decides the money, and it is the part importers almost never see.
Every item has a heading in the tariff, and the rate follows the heading. Similar looking goods can sit under very different rates, and a description that could fit two headings will be classified by somebody other than you if you do not classify it yourself.
We read the invoice, put each line under a heading, and write down why. Where a heading is genuinely arguable we tell you both figures and which one we intend to file, rather than quoting the cheerful number and letting you find out later.
This is also the most useful thing we do before an order is placed. Two suppliers selling what looks like the same machine can leave you with materially different duty depending on how it is built and described, and knowing that while you are still choosing is worth more than any negotiation on price.
A duty opinion is charged as a piece of work and it is free for consignments we then clear.