I get asked that question a lot and there is a ton of misinformation around. Some people who should know better continue to insist that if a person can practice Hypnotherapy legally where they are located, then they are legal to practice in all 50 states via the internet.
I can only speak about the state where I practice, Washington, but where this one in exception, there are probably others.
This state document: MD2014-03 Appropriate Use of Telemedicine describes the delivery of psychological services using telecommunications technologies, and states:
Licensure: Psychologists utilizing telepsychology on patients-clients in Washington State must be licensed to practice psychology in Washington State or have a temporary permit to practice psychology in Washington State. Washington State licensed psychologists are encouraged to be familiar with and comply with relevant laws and regulations when providing telepsychology services to patients-clients across state and international borders.
Now before you try the "but hypnotherapists aren't 'psychologists' argument", let's look at some definitions according to Washington State law.
That same documents states:
“Practice of psychology” has the same meaning as RCW 18.83.010(1) (a)(b)and(c).
And RCW 18.83.010c states:
(1) The "practice of psychology" means the observation, evaluation, interpretation, and modification of human behavior by the application of psychological principles, methods, and procedures for the purposes of preventing or eliminating symptomatic or maladaptive behavior and promoting mental and behavioral health. It includes, but is not limited to, providing the following services to individuals, families, groups, organizations, and the public, whether or not payment is received for services rendered:
(c) Counseling and guidance, psychotherapeutic techniques, remediation, health promotion, and consultation within the context of established psychological principles and theories.
Here in Washington State, hypnotherapists are considered to be "counselors" and are subject to the same regulations. Here's a definition of what the state says a counselor is:
An individual, practitioner, therapist, or analyst who engages in the practice of counseling to the public for a fee, including hypnotherapists. Counselors, for a fee, offer, assist or attempt to assist an individual or individuals in the amelioration or adjustment of mental, emotional, or behavioral problems, including therapeutic techniques to achieve sensitivity and awareness of self and others and the development of human potential.
So, in summary, it's illegal to practice "psychology" over the internet with Washington State residents as your clients unless you are licensed in Washington. "Psychology" legally includes "counseling" and "hypnotherapists" are "counselors". And in Washington state you must be licensed to practice hypnotherapy.
Feel free to challenge that in court, but to claim ignorance or pretend the intent of the law does not include licensed hypnotherapists is just asking to become a test case.
Best of luck with that!