To activate your cell phone online, go to your carrier's website and enter the activation code or the phone's device id, depending on whether the cell phone is prepaid or not. Activating a cell phone online can be faster than calling your carrier because of call wait times.
To activate your cell phone online that is not pre-paid, find the phone's device id. On a smartphone, one way to do this is to dial *#06# and the id displays on the screen. Another way is to go to the phone's settings and find the IMEI, ESN or MEID number. On a basic phone, find the device id inside the phone by removing the battery and locating the IMEI, ESN or MEID number on the inside. Find the number on the phone's packaging or the phone's receipt.
Next, go to the carrier's website and enter the device id. Not all phones are compatible with some carriers so activation might fail. Once compatibility is confirmed, choose a plan to finish activation.
To activate a prepaid cell phone, an activation code is needed sometimes. The code is found in the package that came with the phone and SIM card. If you don't have an activation code, call your carrier or visit the store.