Most Kids stop trick or treating between the ages of 8 to 12 years old.
It all depends on the kids and when they think they're too old for trick or treating but most kids do eventually cease trick or treating by age 12 or 13 at most.
But some kids and teens even trick or treat but some feel they're too old as early as age 8.
But then again some kids never really grow out of the trick or treating and continue to trick or treat until they're 18 years old.
There's nothing wrong with that either as long as they're not out doing any harm and are just having fun trick or treating.
I get some teens and adults trick or treating at my home and I gladly give them candy and have no problem with them trick or treating as long as they are not causing any trouble.