iPhone set up won't recognise my MacBook password

Ive got a new iPhone and during the set up it asked for me MacBook passcode. I typed it in and it said it was incorrect. I tried it again in case I mistyped. wrong. So I typed in my apple password. Still wrong. Typed in the passcode again and it said I'd typed it incorrectly too many times. I can't remember what it said after that but it was something like I would have limited access to something or other. Can anyone help me? I checked on my MacBook and it is definitely correct - assuming it's asking for the one that lets me into it and isn't asking for some other password I don't know about!