There's not really a limit where I live. For the most part, the oldest Trick or Treaters tend to be 13, maybe. I suppose a 14-year-old with 13-year old friends may show up here or there. Also, there's usually a couple of groups of older teens who get a kick out of dressing up (or not bothering to dress up very much at all) and going Trick or Treating with their pals. The older girls tend to like to dress up. The older boys usually do the thing of putting on a ski hat and calling it "a costume". They may be - like - 15 or 16. I don't mind. They're having a good time. It's not a high vandalism area, so the worst I usually see the day after Halloween is usually some candy wrappers that Trick or Treaters (of any age) may have thrown on the ground. Events are held by one group/organization or another, for kids of all ages; but Trick or Treating is "its own thing" that a lot of kids just enjoy doing in addition to going to the events. In the "scheme of what teenagers do for fun", I think Trick or Treating is one of the more harmless - even positive - things. :) (Where I live, kids that are only 13 most often still have a parent or friend's parent standing down at the street, while the 13-year-old Trick or Treaters do door-knocking thing; so it's really usually only a couple of groups of kids older than that who show up.