On the ops desk the commercial invoice is the document the rest of the file gets checked against: the values, party details, and cargo description it carries must line up with the shipping instruction and the downstream customs filings, because a mismatch surfaces as a customs hold at destination. The decision it drives is whether a file is ready to clear, since customs requires the commercial invoice, not the proforma, for import processing. It is not the same as a proforma invoice, which is a pre-sale quotation issued before the goods ship and carries no payment obligation; the commercial invoice documents the actual sale and travels with the shipment for clearance.
Glossary
Commercial Invoice
The seller's bill to the buyer for goods shipped, and the primary document customs uses to determine the value of a shipment and the duties and taxes owed.