Landed cost stacks in a fixed order, and the order is the whole game. First the customs value: in most import regimes, the goods PLUS the freight and insurance to get them there — the CIF basis. Duty is a percentage of that. Then the import VAT or GST is charged on the customs value plus the duty — a tax on a tax, disliked by everyone and applied by nearly every VAT regime anyway.
The classic error is computing the tax on the goods value alone. It looks reasonable, it is how domestic sales tax works in some places, and on a DDP quote it under-collects on every single file — the freight, the insurance and the duty all escaped the base. The tool prints the wrong-base figure next to the right one precisely because the difference is the argument: on the default numbers it is a four-figure gap on one shipment.
A Hong Kong forwarder runs this arithmetic for the other side of the border and beyond, not for home — Hong Kong is a free port with no VAT and duty on almost nothing. Which is exactly why the desk needs the tool: your own market never drills the habit, and the first DDP quote into a 13% VAT market is where the habit's absence gets expensive.
In nearly every VAT/GST regime, yes: the import tax base is the customs value plus the duty (and often excise). It reads like a tax on a tax because it is one. The practical consequence is that a 6.5% duty under a 13% VAT actually costs 6.5% × 1.13 ≈ 7.3% of customs value once the cascade is counted — and a DDP quote that misses the cascade is short by exactly that difference.
The transaction value of the goods, plus — in CIF-basis regimes — the international freight and insurance to the border, plus certain additions customs law prescribes: assists, royalties tied to the goods, packing. Not included: post-import transport, destination brokerage, and (where separately shown) some destination charges. The invoice price alone is the starting point, not the answer.
Because the quote is for the customer's border, not yours. The moment you offer DDP or advise a mainland, European or Southeast Asian consignee on their to-door figure, you are pricing someone else's duty and VAT regime — and importing into the mainland from Hong Kong involves import VAT on exactly this cascaded base. Hong Kong's own free-port status is precisely why the habit has to come from a tool instead of daily practice.
Under DDP the seller pays everything to door, including duty and import tax — which creates the recovery trap: import VAT is usually only reclaimable by a party VAT-registered in the destination, and a Hong Kong seller usually is not. The tax then becomes a real cost instead of a flow-through, which is why experienced traders prefer DAP with the buyer as importer of record, and why a DDP quote should price the VAT as unrecoverable unless someone has confirmed otherwise in writing.
Cargo-Stack reads the enquiry, prices it against your own rates, and drafts the quote — with this arithmetic underneath it. Same maths, no retyping.
Try it on a real enquiry