It depends on your genetics, how high your dose is, etc.
Pre-T, I had some hairs on my upper lip, and a few chin hairs and faint sideburns. I'm now a little over six months on testosterone, and what appeared first was hair around my chin and jawline, which slowly crept up to my sideburns, and now my mustache is fairly visible. I can't grow a beard, yet, but a fairly weak chinstrap - it all looks rather prepubescent anyhow so I shave it off.
I hope my sideburns come in thicker in a few months, though.