英语翻译按照以往我公司通常都是收到货款后确认收入,那么从现在开始是否可以按照这封信的要求以后只要取得发票的时候就确认收入

意思比较累赘,但是可以考虑以下说法：
“According to nromal practice,our Company will confirm revenue income upon receipt of payment,so can we now agree according to this letter that either when the official invoice is issued/obtained that we confirm revenue income,or when you acknowledge that the official invoice is correctly issued that we confirm revenue income?”
这里似乎是要对收入的定义或如何处理做一个决定,不管是会计是还是计算业绩、佣金等等用途.以上是对原文的完整翻译,对方应该也能够理解清楚你的意图.另外,发票在国外通常也可以叫作 “official receipt”
希望对你有用.

According to the past my company is usually after receive payment confirmation income，So from now on whether can be in accordance with the requirements of this letter after obtain bill as long as when he confirmed to your income or the invoice when confirmed our reconfirm income?

According to the past experience, our company is along with the method of the confirmation of the income after receipts of the goods. So, requested in this letter, can you, from now on, adopt the meth...