Why Carton Data Belongs in Your Payment Terms

“When the cartons arrived, the freight invoice was bigger than the quote — and we had already paid the balance.” That is the part of sourcing nobody warns a first-time buyer about. The packing data your supplier sends you is not paperwork. It is the number your forwarder prices, books and bills.

Here is the mechanic. Carton dimensions turn into cubic metres: length × width × height ÷ 1,000,000. LCL sea freight bills on the greater of volume and weight, at 1 CBM = 1,000 kg. Air freight divides cubic centimetres by 6,000; express often by 5,000. The carton is not packaging — it is the billing unit.

A worked example

Say you consolidate 180 cartons from two suppliers, specified at 60 × 40 × 40 cm and 13 kg gross each. That is 0.096 CBM per carton and about 17.3 CBM for the order — roughly 2.3 tonnes, so the shipment is light cargo and LCL bills on volume.

Now suppose the supplier packs into a stock carton that is 5 cm taller: 60 × 40 × 45 cm. Per carton that is 0.108 CBM, and about 19.4 CBM for the order — some 2.2 CBM more than you booked. Billed by express, the same 5 cm adds 2.4 kg of volumetric weight per carton, around 430 kg across the order. Nothing about the goods changed. Only the box did.

That is why carton dimensions belong in the specification. They decide what you pay, how many cartons sit on a pallet, and whether the delivery window you were promised still holds.

What to tie the balance to

The trap is paying the balance against a status you cannot check: “production finished”. A status is not a fact. Hold the balance instead against the measured packing list — carton count, outside dimensions, gross weight per carton, and a note saying whether those figures were measured or estimated — and release it against the Bill of Lading, once the goods are physically with the forwarder.

If you want a second pair of eyes on the packing data before you book — or before you release the balance — that review is part of our sourcing support. Ten minutes with the numbers beats a dispute two months later.