✔ 最佳答案
Yes... No problem... As if you are in Hong Kong, you will require to change your ID card within 30days after your 18th birthday...
Since it will still be within 30days boundary when you return to Hong Kong, there is be no problem for you...
However, if you wont be in Hong Kong during your birthday and will not return to Hong Kong within 30days of your birthday... You will require to change it once you get back to Hong Kong...