8820 as backup to Tour 9630

OK, my nephew is giving me his 8820 for a backup (he is upgrading to a newer BlackBerry). I have Verizon; he has AT&T...

I have a Tour 9630.

If I should need to use the 8820 in place of the 9630, what all do I need to do???

Is there a SIM card that needs changing??? Does he need to keep his SIM card for his new BlackBerry???

Do I need a new SIM card (or will my Verizon card work)???

Will it require re-activation from Verizon???

Will the AT&T 8820 work at all with Verizon???

Thank you for any comments!

well technically if you have verizon you can't use the 8820 as a backup since it is a GSM phone that uses SIM cards.

So basically you can't use the 8820 on Verizon's network.

EDIT: although the tour has a SIM card preinstalled in it, that still will not allow you to use the 8820 on verizon's network