“书面通知”常见的英文表达是 written notice 。
例句:
You must give a written notice at least one month in advance if you want to resign.(如果你想辞职,必须提前至少一个月给出书面通知。)
The company issued a written notice to inform all employees of the new policy.(公司发出了一份书面通知,告知所有员工新政策。)