if the exporter's bank has not confirmed the documentary credit but only advised him of it,the exporter will not be paid until the issuing bank has checked the documents and transferred the money or accepted a bill of exchange
the next stage is for the importer's bank to debit the importer's account. the importer must pay his bank in order to get the documents. without the documents, and in particular without the bill of lading the importer cannot collect the goods.