Generate a compliant commercial invoice for an international shipment programmatically, including required fields for customs clearance

Steps

1. Collect all required fields: seller name and address, buyer name and address, invoice date, invoice number, incoterms 2020 term and named place, country of origin, and currency of sale
2. List each line item with: HS code (destination-country extended), precise goods description, quantity, unit value, total value, and net/gross weight
3. Calculate the total invoice value; for goods subject to ad valorem duties, ensure the declared value matches the actual transaction value as defined under WTO Customs Valuation Agreement
4. Add any required certifications such as a country of origin declaration or a preference claim referencing an applicable Free Trade Agreement
5. Render the document as a PDF using a repeatable template engine; ensure the layout meets the carrier's ETD (Electronic Trade Document) upload requirements
6. Attach the PDF to the carrier API shipment request via the relevant documents endpoint (e.g., FedEx ETD or UPS PaperlessDocuments)