Once I have confirmed the delivery fee, I will send you the estimate and the invoice.
Once the shipping fee has been decided, I still send you the estimate and the invoice.
「送料が確定しましたら見積書と請求書をおくります。」は英語ではこのようです。
Once I have confirmed the delivery fee, I will send you the estimate and the invoice.
Once the shipping fee has been decided, I still send you the estimate and the invoice.
「送料」は英語では delivery fee や shipping fee に相当します。
「〜確定する」 → to have be decided, to confirm
「見積もり」→ estimate
「請求書」→ invoice, bill
ご参考までに。
Once the shipping fee is confirmed we will send the quotation and the invoice/bill.
We will send you the quotation and the invoice/bill when the shipping fee is final.
まずメインの単語ですが、
送料＝shipping fee
見積書＝estimate, quotation
請求書＝bill, invoice
確定＝ confirm, finalize, final, decided
となります。
Once the shipping fee is confirmed / when the shipping fee is final = 一度送料が確定したら、送料が確定したら
we will send the quotation and the invoice = 我々は見積書と請求書を送ります
アメリカ合衆国 
日本 
