Re: if we purchase i phone already used one what is the way to activate
If it's on someone's account that's in arrears - you can't... if it was on Sprint, it's locked to Sprint... if it was on Verizon, it can be used on Verizon, or any GSM carrier... If Sprint/Verizon - you have to have them add the MEID to your account, and insert a SIM for the particular network... if a GSM carrier - just install an SIM for that network.