港澳生第一次申辦的效期為三年，第二次延期申請的效期為一年。
僑生及外籍生的居留證效期僅為一年，每年需辦理線上延期。
For international and overseas students, the validity is 1 year; it is required to extend it every single year.

何時需要申請延期？When do I need to apply for an extension?
居留證到期日前30天需線上申請
舉例：居留證到期日為7月30日，可以線上申請的日期為6月30日。
30 days earlier before the expired date on your ARC
Ex. The expired date on your ARC is July 30th, and you may extend it on June 30th.