Can I use my existing cell phone from an old monthly plan for a prepaid account?

dbpubs:

It's a bluetooth-capable Nokia [model nr. Unknown], I have cable and backup software tricks to the laptop and do not want to lose that.

with ATT I know all you have to do is connect the prepaid sim and you are it will work very well for you.

Any other carrier, I can not promise the same work, but it entails. No.