他们一向按时付款。

They always pay punctually.

《牛津词典》

假如您能按时付款的话我们将不胜感激。

We really appreciate if you could send us the payment on time.

youdao

于是，他开始给员工和那些按时付款的客户写感谢信。

So he wrote appreciation notes to his staff, and sent similar notes to clients who paid their bills on time.

youdao