The packing list is the document nobody remembers until an officer opens the container. At that moment it becomes the most important one of all, because it’s the only one that says what’s inside each package.
The commercial invoice says what the shipment is worth. The Bill of Lading says who claims it. The packing list says where each item physically is — and that’s what turns a two-hour inspection into a two-day one, or the other way round.
What it’s actually for
It isn’t a bureaucratic box to tick. It has three concrete uses:
During customs inspection. If your shipment draws the red lane, the officer needs to locate specific goods inside a container. With a list that says “carton 14 of 60: 200 pieces of model X”, the check is targeted. Without one, everything comes off.
To reconcile quantities. It’s the bridge between the invoice, which speaks in pieces and money, and the B/L, which speaks in packages and kilos.
To claim damage. If something arrives broken or missing, the list is the evidence of what was in which package. Without it, your cargo insurance has far less to work with.
What it must contain
There’s no single official format, but a list that works includes:
For the shipment as a whole:
- List number and date, and a reference to the invoice it covers.
- Supplier and consignee, with the same names used on the invoice.
- Container and seal number, once known.
- Total packages, total gross weight, total net weight and total volume.
For each package, one by one:
- Package number — “1 of 60”, not “several cartons”.
- Shipping marks and numbers physically on the carton.
- What’s inside: description, model or part number, and quantity.
- Gross and net weight of that package.
- Dimensions, if the shipment is bulky or palletized.
- Pallet number, where applicable.
The golden rule: somebody who has never seen your goods should be able to find a specific piece without opening every box. If your list doesn’t allow that, it isn’t a packing list; it’s a summary.
The cross-check customs runs
The list is almost never read on its own. It’s read against the other documents:
| Data point | Must match |
|---|---|
| Total pieces | The commercial invoice |
| Number of packages | The Bill of Lading |
| Gross weight | The B/L and the container’s real weight |
| Description per line | The invoice and the entry |
| Container and seal | The B/L and the physical container |
When two documents say different things, somebody has to explain why. And that explanation costs time with the container already on the ground. It’s one of the fields where import files most often break.
Units, where it falls apart
The most common error isn’t false data: it’s a different unit on every document.
The invoice says “20 cartons”. The list says “480 pieces”. The B/L says “20 packages, 640 kg”. All three can be right and still not reconcile at a glance, because nobody wrote down the conversion.
The fix is one line: have the list state both units — “20 cartons · 24 pcs per carton · 480 pcs” — and make the per-package weights add up exactly to the total gross weight.
Net weight and gross weight are not the same
It sounds obvious and it gets confused constantly:
- Net weight: the goods alone.
- Gross weight: the goods plus packaging, carton and pallet.
It matters because there are tariff lines whose unit of measure is the kilogram, and there the weight isn’t a logistics detail: it’s the base of a duty. If the list blends the two concepts, the entry can end up wrong for a reason that has nothing to do with price.
Mistakes we see often
- “Said to contain” and nothing else. Useful to the carrier, useless to customs.
- Lists that give only totals, with no per-package detail.
- Unnumbered packages, impossible to locate inside the container.
- Per-package weights that don’t add up to the declared total.
- Descriptions that differ from the invoice for the same goods.
- A list issued before consolidation, no longer reflecting how the container was actually loaded.
- Goods from several invoices in one shipment without saying which package belongs to which.
That last one causes the most trouble in consolidated shipments, and it’s solved with one column.
The list you ask for, not the one you get
As with the invoice, this is fixed before shipment. Send this to your supplier and make it a condition of the order:
Packing list requirements — shipments to Mexico
- Packing list number and date, referencing the commercial invoice number.
- Seller and consignee, with the same names used on the commercial invoice.
- Container and seal number, once known.
- One line per package, numbered “1 of N”.
- For each package: shipping marks, contents with model or part number, and quantity.
- For each package: net weight and gross weight, plus dimensions if palletized or oversized.
- Pallet number, where applicable.
- Totals: total packages, total net weight, total gross weight, total volume — the per-package figures must add up to them.
- Quantities stated in both units where they differ (e.g. “20 cartons · 24 pcs per carton · 480 pcs”).
- If the shipment covers more than one invoice, indicate which invoice each package belongs to.
At TradeWay
We cross-check the packing list against the invoice and the B/L before the shipment leaves, and request corrections while they’re still an email rather than a held container. One point of contact and one invoice for the whole operation. If your shipments tend to get stuck in inspection, get in touch: it almost always starts here.
