How far must Peyos extend down?

To the bottom of the ear lobe or the bone next to the ear?

Answer:

There are opinions in the matter, whether till the bone or until the very end of the ear. The consensus seems to be that despite the fact that the Shulchan Aruch writes to the end of the ear, it really is sufficient until the bone. It has been suggested that the expression of the end of the ear is as an extra stringency because people have a hard time assessing the exact place.