A cell phone that has been pre-owned or pre-activated needs to be reactivated through a service provider before you can use it. You can only activate pre-used cell phones if they have not been reported stolen. If the phone you are activating does have an unpaid or outstanding balance, the balance will be transferred to the new account and will be part of the next bill unless otherwise specified by the service provider. If you purchased a used cell phone, contact the service provider representative to confirm that there is no outstanding balance in case the phone is indeed reported stolen.
Open the phone's battery compartment and locate the SIM card. Find the phone's IMEI code, which will be a combination of letters and numbers. Depending on the model of your phone, the code will either be right beside the SIM card on a sticker or behind the battery. Write it down.
Contact your service provider of choice to check the status of the phone. Give the representative the IMEI code to confirm whether the phone was reported stolen. The representative will also inform you about any unpaid balance.
Go to the service provider's website if the representative approves the phone for activation. You can activate the phone on the website without paying additional fees. The unpaid balance will be transferred to this account.
Click on the section of the website that suggests activating a new phone. It will ask you for your personal information, address and email. It will also ask you for billing information and your choice of phone number. Use the IMEI number to activate the phone.
Wait for the required amount of time as specified by the website for the activation to take place. This can be anywhere for half an hour to several hours. Once the phone is activated, check its status on the website. While some service providers will require the unpaid balance before you can freely use the phone, others will simply add the unpaid balance to your first bill.