“收费标准如作更改恕不预先通知”英文翻译

The charging standards is subject to further emendations. Notice in advance might not be made.

（pls be well noticed that ）it will not inform in advance if the standard for charges change.
或者 （pls be well noticed that ）the standards for charges are subject to change withouth notice in advance.
告知是一般会加上（please be well noticed that ）