I got mine at 8 weeks, or a few days after.  But my last Yorkie, lacked 2 days of being 8 weeks.  I wanted to take her early, as she was small, and I wanted to make sure she ate, and cleaned her up some.  The breeder knew me, so there wasn't any problem.  I am glad I did, because after I got her home (two days later), she was broke into, and someone took her Yorkies.  3 puppies and her stud.  
