There are a couple of reputable and long-standing organizations (guilds and associations) who train and list hypnotherapists in the US and internationally.
Here are a few:
National Board of Hypnotists
National Guild of Hypnotists
National Federation of Neuro Linguistic Programming
American Hypnosis Association
American Society for Clinical Hypnosis
There are British entities that function similarly as well.
You can also look up the omnihypnosis training Centre which is an American business that has recently been relocated to Switzerland.
