You will need a service provider through which you can activate the used cell phone. This can be Sprint, Verizon, AT&T or any other service provider. Contact at least a couple of service providers and ask if they offer a plan which allows you to activate a used cell phone. Once you have finalised the service provider, choose a plan that best suits your needs.
In order to make sure that your used cell phone is compatible with the service provider of your choice, you will have to provide the cell phone’s Electronic Serial Number (ESN). It is inscribed on the cell phone beneath the battery. Remove the battery and note down the number.
Another thing you have to ensure is that the used cell phone is not locked with a particular service provider. Look for a service provider logo beneath the battery. If you see a logo there, you can only activate the cell phone with that particular service provider.
Once the phone’s compatibility has been established and you have chosen the right service provider, make a contract with the service provider and acquire a SIM card. Install the SIM in the used cell phone according to the instructions given by the service provider.
If it is not your first cell phone, you may want to keep the same cell phone number that you were previously using. To do so, ensure that the used phone supports your old SIM card. If it does not, you might have to get the SIM card replaced.