If you have an Apple or an Android phone—and you probably do—you have the option of locking your phone using a PIN code. With most of these phones, you can choose a four-digit PIN or a six-digit PIN.

Have you ever gotten a new phone only to find out it’s locked to a specific carrier? This often happens when you purchase a subsidized phone from a carrier. The carrier locks the phone so you can’t ...

Update, May 26, 2025: This story, originally published May 24, has been updated with a brief history of PIN codes, information regarding the most secure codes you can use and why 8068 really isn’t the ...