Default activating phone from an upgrade not yours

quick question... my scenario is that I used my wifes upgrade to get the m8 and phone just came in today. She is taking my s4. Do I need to first activate it under her account and then do the switch or can I just go online and activate it directly under my account? We have two separate accounts. Just seems tedious to have to first activate it on her account and then do the switch. THanks!