Passcode to use to Enable iCloud in my devices

I'm trying to enable iCloud Data Syncing in a new macBook, so I get asked for passcodes of my iPhone and the other macBook. I use the codes that work to unlock both devices but I keep getting "incorrect passcode" as response. Don't know why the passcodes I use work to unlock the iPhone and the other macBook but don't work for authentication. Please help how to proceed !