Proforma is from the Latin word "as a matter of form" or "for the sake of form".
Normally means that the invoice is estimated and not definite.
It is not a true invoice, it is a document that states a commitment from the seller to sell goods to the buyer at specified prices and terms.
A Proforma Invoice is generally raised when the seller is ready for dispatching the goods but want the goods being sent before dispatch.
Custom invoice
Custom invoice is normally use for export declaration.
Commercial invoice
Commercial invoice is used when the commodities shipped are being bought or sold.
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