Why cant i turn on usb debugging samsung galaxy s5 lollipop

[Nathan Pfaltzgraff]

Followed the steps to allow usb debugging by tapping on the build number and went to developer options only to see a greyed out usb debugging option

 

[Rukbat]

Your carrier evidently doesn't allow you to turn debugging on. Your only option is a custom ROM that does. (Let us know who the carrier is, so that everyone can stay away from that phone.)