Gross weight vs net weight on a packing list: how do you check that the lot rows add up?

Net, gross and tare

Net weight is the product alone: for frozen meat, the meat. Gross weight is the product with its packing: the meat plus cartons, liners and labels. Customs definitions say the same thing. Net mass is the weight of the goods without any packaging; gross mass is the goods with their packaging, but without the container or other transport equipment. The difference between the two is the tare of the packing.

Two more weights belong to the container. The empty container has its own tare weight. The verified gross mass (VGM) is the gross weight of the cargo plus the container's tare. Since 1 July 2016 the SOLAS convention has required the shipper to give the VGM to the carrier before the container is loaded.

For frozen meat in cartons, gross is always higher than net, because every carton, liner and label adds its own weight. Only goods with no packing at all weigh the same gross and net.

Which weight goes where

Frozen meat is normally sold by net weight, so the invoice shows net. The bill of lading shows the gross weight the shipper declared. The carrier does not weigh the cartons inside a sealed container, which is why bills of lading say "said to contain" or "shipper's load and count", and banks accept that wording (UCP 600, article 26(b)). The packing list shows both, per lot and in total. The health certificate usually shows net weight, often split by product.

So the invoice and the bill of lading normally print two different weights for the same container, and both can be right: they measure different things.

Lot rows and totals

A packing list for frozen food usually has one row per lot or product: the lot number, the number of cartons, the net weight and the gross weight. A total line closes the table. The answer to the question is plain arithmetic: in each column, the rows must add up to the printed total, and those totals are the figures the invoice, the bill of lading and the health certificate repeat.

Plain arithmetic is not always easy. The documents of one container come from different offices, sometimes in different countries and number styles, and a United States supplier may give weights in pounds. One pound is exactly 0.45359237 kg, the value in the US National Institute of Standards and Technology's tables.

Why the rows matter when the totals agree

Under a letter of credit, banks check totals. ICC banking practice says they examine the total quantities and weights on a packing list against the credit and the other documents, not the arithmetic inside it (ISBP 745, paragraphs A22 and M6). So the bank will not add up your lot rows. The buyer, the cold store or an inspector who counts cartons by lot may.

In the Philippines, importing more than the volume stated on the import documents is one of the adverse findings that meat inspectors act on at the cold store. And if the VGM is calculated by adding up the cargo and the container tare, a wrong gross weight goes straight into it. The United Kingdom, for example, has set an enforcement tolerance for a declared VGM of 5% or 500 kg, whichever is greater.

An example

Vale Frio Foods ships one reefer container of frozen pork to a buyer in Manila (the name is made up). Its packing list has two lot rows:

542 and 578 cartons make 1,120, and the rows add up to 28,000 kg net and 28,896 kg gross, as printed. The invoice and the health certificate state 28,000 kg net and the bill of lading 28,896 kg gross: each document shows the weight it is meant to show, and the figures agree.

The draft bill of lading, however, says 1,210 cartons, where every other document says 1,120. Two digits are swapped. The draft must be corrected before the original is issued, or the set will carry two different carton counts.

For the other values that must agree between documents, see what must match between the bill of lading, invoice and packing list. For the whole set, see the export document checklist for a frozen container. Under a letter of credit, data that conflict between documents are a common reason for refusal: see letter of credit discrepancies. The terms are explained in the shipping document glossary.