翻译的不错啊 不过不清楚你是站在买方还是卖方的角度上说的
我觉得按你这么说已经可以了 挺清楚了 要改的话 也就是把主语改成买方 因为是要让买方知道吧 所以可以这么写
The buyer should deposit in advance 30% of the total payment to the seller 7 days before the seller delivers the goods to the buyer's shipping agent.
如果一定要加重语气的话 干脆这么说
The deadline for the buyer's deposit to the seller,which is 30% of the total payment,is seven days before the seller delivers the goods to the buyer's shipping agent.
不知道说得准不准确 不过一般都不这样用的 因为语气太强烈了.