請先告知貨品的有效期後, 才通知回訂貨量
I will confirm the order quantity after you let us know the product's expiry date. Thanks.
更新1:
如果在前面先講: We would like to order the tins later.
更新2:
Please inform us the tin's date of expiry, after that, we will place an order with you. 如果這樣又如何?