Short answer: every line item needs a concrete description, quantity, value, currency, country of origin, and HS code, plus seller and buyer details, total weight, and the correct Incoterm. Vague descriptions and missing origin data are what get parcels pulled for inspection. The invoice and the electronic declaration must agree, because customs works from the electronic record and treats mismatches as a reason to look closer.
The fields customs actually checks
EU customs declarations pull from a fixed set of invoice fields. The non-negotiables: seller name and address, buyer name and address, a clear description of each item (not just a SKU), quantity, unit value, total value, currency, country of origin per item, HS code per item, total shipment weight, and the Incoterm used for the sale. Miss any of these and the declaration either gets rejected by the broker's system or lands on a customs officer's desk for manual review.
The description field causes the most trouble. "Apparel" or "accessories" is not a description for customs purposes. "Women's cotton crew-neck t-shirt" is. Vague descriptions are the single most common reason small parcels get flagged for inspection, because the officer cannot match the description to the declared HS code and has to open the box to see what is inside.
Values must reflect the real transaction value, including any discounts actually applied. Declaring a lower value to reduce duties is misdeclaration, and customs authorities cross-check declared values against the seller's website pricing. Brands caught undervaluing face reassessment, penalties, and in repeat cases, shipment seizures.
Country of origin and HS codes, per line
Every line item needs its own country of origin and HS code, even when a parcel contains products from multiple countries. A box with a shirt made in Vietnam and a cap made in Bangladesh needs two origin declarations, not one. Getting this wrong means the wrong duty rate is applied, which is either money lost or a compliance exposure depending on the direction of the error.
The HS code on the invoice should match the code used in the electronic declaration. When the two disagree, the electronic record usually wins the argument and the invoice looks like an afterthought, which is exactly the impression that triggers deeper scrutiny. Keep one source of truth for HS classification and push it to both the invoice template and the shipping system.
Common invoice mistakes that delay clearance
The usual suspects: currency missing or ambiguous (USD stated explicitly, not assumed), the Incoterm field blank or wrong (DDP on the checkout page but DAP on the invoice creates a mismatch the broker has to resolve by phone), no EORI or IOSS number where one is required, and gift or sample designations used to dodge duties on commercial sales. Customs officers see these daily and treat them as signals, not accidents.
Another quiet killer is the invoice number format. Some brands regenerate invoice numbers on reprints or use the same number across shipments. Each commercial invoice needs a unique number that matches the shipment records. Duplicates cause the broker's system to flag the second shipment as a possible duplicate declaration.
Paper versus electronic invoices
For express shipments, the electronic commercial invoice submitted through the carrier's system is what customs works from. The paper copy in the pouch is a backup. Brands that only prepare one of the two discover the gap when a shipment is held: the electronic record says one thing, the paper says another, and nobody clears the parcel until they agree.
Generate both from the same data at the same time. If your 3PL or carrier platform auto-generates the electronic invoice, verify what it puts in the description and value fields before the first shipment, because the defaults are often the vague kind of descriptions that cause inspections.
Questions buyers ask
Can I mark a commercial shipment as a gift to lower duties?
No. Misdeclaring a commercial sale as a gift is customs fraud. EU authorities routinely check declared values against the seller's public pricing, and the penalties scale with the underpayment.
Does the invoice need to be in a specific language?
English is accepted for EU customs purposes in practice, but the goods description should be concrete enough to translate. Vague terms cause more problems than language choice does.
What is the difference between a commercial and a proforma invoice?
A commercial invoice documents a completed sale and supports the customs declaration. A proforma invoice is a quote or estimate, used for samples or advance documentation. Only the commercial invoice clears a sold shipment.