Expiry date of mobifone sim card

I have a Mobifone pre-paid sim card. If i don't top up the card, how long can the card be used before it expire ? - once expired then the sim card cannot be used anymore. Some people tell me is 100 days, some people say is 1 month. Appreciate if you can advise me if you know. Thank you in advance.

the problem is that u used it ?, if u never open or use it, u dont worry, expiring it will be one year

dial *101# from your phone, this will show your current balance and expiry date.

It depends their package. Follow instructions of user "Laidbackfreak":D
Or follow this link:
Trip Advisor

Hi all,thanks. I got all the answers that I am looking for.