Ask any customs broker what causes the most avoidable delays on China imports, and they'll give you the same answer: bad paperwork. Specifically, the commercial invoice and the packing list. These two documents travel with every international shipment, and customs officers at every destination port will compare them — against each other, against the cargo, and against whatever their databases say your goods should be worth.
Getting them right isn't complicated, but it does require attention. Here's a practical breakdown.
The Commercial Invoice
The commercial invoice is the primary document customs uses to assess duties and taxes. It's the record of the transaction between buyer and seller.
What Must Appear on a Commercial Invoice
- Seller's full name and address — must match the export license and business registration
- Buyer's full name and address — must match the consignee on the Bill of Lading
- Invoice date and number — sequential numbering helps if you're importing regularly
- Description of goods — specific enough to classify under the HS code system; "electronic components" is too vague, "LED driver ICs, 12V DC input" is not
- Quantity and unit of measure — pieces, kilograms, meters, cartons — be consistent with what's physically in the boxes
- Unit price and total value — in the agreed transaction currency; if you're paying in USD, the invoice should be in USD
- Country of origin — China in most cases, but this matters enormously for duty rates under trade agreements
- Incoterms — FOB, CIF, EXW, etc. (see the full Incoterms breakdown). Customs uses this to determine whether freight and insurance are included in the declared value
- Payment terms — T/T, LC, etc.
The Value Question
Customs duty is calculated on the customs value, which in most countries (and under WTO rules) is the transaction value: what you actually paid for the goods. If you declare lower than that to reduce duties, you're committing customs fraud. The penalties — seizure, fines, blacklisting — are much more expensive than whatever duty you were trying to avoid.
If you received a trade discount, that's fine to include — just make sure there's a clear record of it. If your supplier issues a pro forma invoice at a different price than the actual commercial invoice, customs will want to know why.
The Packing List
The packing list is the physical inventory of the shipment. It doesn't set customs value — that's the invoice's job. What it does is let customs officers verify that what's in the boxes matches what was declared.
What Belongs on a Packing List
- Reference to the commercial invoice (invoice number and date)
- Carton or package number — e.g., "1/20, 2/20..." up to the total number of packages
- Contents per carton — quantity and description of what's inside each package
- Net weight per carton — the weight of just the goods
- Gross weight per carton — goods plus packaging
- Dimensions per carton — length × width × height in centimeters or inches
- Total net weight, gross weight, and volume — the summary line at the bottom
Carriers need the weight and dimensional data to calculate freight charges and assign container space. Customs needs it to verify the declared quantity. Your warehouse team needs it to unload and count stock efficiently.
Why Mismatches Cause Delays
This is where things break down. Customs officers routinely compare the invoice and packing list side by side. If they don't agree, the shipment gets flagged.
Common mismatches:
Quantity discrepancy. The invoice says 5,000 units. The packing list shows 250 cartons × 22 units = 5,500. Which is it? Now someone needs to open boxes.
Weight inconsistency. The packing list says total gross weight 1,200 kg. The shipping line's manifest (based on what was weighed at the port) says 1,380 kg. This triggers a VGM (verified gross mass) query and potentially a physical inspection.
Description mismatch. The invoice says "plastic household goods." The packing list says "acrylic storage containers, non-hazardous." Customs wants one consistent description that can be HS-code classified.
Value vs. quantity math. Invoice total is $12,000 for 3,000 units. That's $4 per unit — but the same product shows up in customs databases at $8–$12 per unit. Now you're dealing with a price verification query.
Physical inspections triggered by paperwork problems typically delay a shipment by 3–7 working days at port. Add detention and demurrage charges at $100–$200 per container per day, and a small document error becomes a $500–$1,400 problem fast.
Practical Tips to Get It Right
One person owns the document preparation. Fragmented responsibility — supplier prepares the invoice, forwarder prepares the packing list, you review neither — is how mismatches happen.
Match the B/L description exactly. Whatever description appears on your Bill of Lading must be consistent with what's on the invoice and packing list. Three documents, one description.
Don't round weights. If the actual weight is 847.3 kg, write 847.3 kg. Rounded numbers look suspicious.
Keep a template and update it for every shipment. Suppliers sometimes reuse old invoice templates and forget to update quantities, prices, or dates. Build a checklist you run against every document set before the shipment leaves.
For a faster picture of your total landed cost — duties, freight, and all fees included — the ChinaLogisticHub Estimator lets you build an estimate in minutes using your actual HS code and shipment details.