Not sure how to describe it, but AFAIK roaming will be charge accordingly.
what I want to ask is to keep the line open just to receive call when I'm in SG. will there be any charges?
I know there is charges upon receive call, just want to know is there any charges on idle (not using).
(data off / 2G only)

apologize if my question is uncertain

yes, when u answer call when roaming in SG, there will be roaming charges imposed based on time.

No charges if line is active as long u don't answer phone.

Hope it helps

great. thanks for the clarification.
i'm estimating if my package will arrive my office and scare if require custom clearance, the postage co. unable to get to me.
thanks again