After upgrading to an iphone 3gs, is it ok to swap sims and use old phone

[stealthieOne]

So now I wanted to know is it ok to do this...

I took my daughters sim card out of her phone (not an iphone) and put it in my old iphone 3g.
Is there a problem with doing that. I dont need her having data access. I tried it and it doesn't work. thats how I want it.

I really just want to know will I incur any crazy charges? Is it ok do this?

 

[Rayfire]

If her line doesn't include any data plans, charges will apply if by some chance she
accidentally used data because of the iPhone's capabilities (i.e. Mail, Weather)

EDIT:
Ok I didn't seem to get initially your first post, as long as your daughter's sim card
has an iPhone data plan on it, it's safe to use it on your old iPhone 3G.

 

[TK2K]

yup, as long as you have an iphone data plan sims can go wherever, a 2g iphone, a wimo phone, anything else.