need info on switching sim cards please

i bought a new 710 from nextel to replace a phone i lost. when i got the phone i
wanted to use that phone with a i60 sim card and it worked. i put the 710 sim in an other phone that i cancelled. now that info is this on the phone and i need to call nextel to turn service on . will they know what i did?

it depends if the card will even work with nextel.Is is a simcard that was on nextel originally? SIMs dont really have anything to do with the phone, and chances are if you want to activate service on a phone, they will want to send you a new sim card.

it doesn'tmatter, as long as the phone is not reported stolen you can used whatever Nextel phone you want with that sim card. and yes it can be tracked.