And of course now it turns out Fae can enter no problem whenever they want as long as they mean the residents no harm. It's a lot less likely with the more malevolent entities out there that they'll mean no harm, but it's theoretically possible they could freely enter as well.
Unlikely as Harry can not even enter a close friend's home without an invite and the only time he ever did so while meaning the occupants anything even close to harm would be when he stole back Bob. Granted Mortals have that whole conflicted thing where he might still be holding a tiny bit of a grudge that they stuck him with the bill last time they went to burger king or something but I'm kinda going to lean towards Fae being a special case.
Remember also that in GS,
Molly is able to enter Murphy's house under a veil without specifically being invited in.