Trading SIM cards

[SandAngel]

Willthere be anything that WON'T work when my Mom transfers her postpaid sim into a prepaid phone?
I read BES doesn't work but that doesn't matter. What about everything else? Also is there something that might still work but just differently ... Like slower speeds or anything like that.

Also need to know if it matters which phones you are using as I know sometimes different phones do different tricks.

Thanks

[Armando175]

A few months ago, my moms Samsung T639 got messed up so I went to buy the Samsung T139 for $19.99 at Walmart which was prepaid. I stuck the postpaid SIM card into the prepaid phone without any issues. Everything worked just fine. Out curiousity, I even inserted my SIM card from my 9700 into a Motorola dunmphone and it worked just fine except for BIS of course. This is from my experience. You shouldn't have any problems.