This is the question people are most reluctant to ask before booking, which is exactly backwards. Ask it on the phone, before you have paid anyone or sat in a room.
The default is no touch
Somatic Experiencing, Sensorimotor and most somatic psychotherapy are conducted entirely in conversation, with you sitting in a chair. If you assumed body-based meant hands-on, that assumption is wrong for the large majority of practitioners in this field.
So if touch matters to you either way — you want it, or the idea makes you cold — you need to ask, because you cannot infer it from the label.
Where it does get used
Some Hakomi practitioners use supportive contact. Some SE practitioners trained in the touch modules use hands-on work. There are also whole disciplines next door — craniosacral, bodywork, massage therapy — that are not psychotherapy and are not regulated as psychotherapy, though they sometimes market themselves in the same vocabulary.
That last distinction matters more than it sounds. A licensed psychotherapist using touch is doing so inside a scope, with a board that can act. A bodyworker offering trauma release is not, whatever their training was.
What good consent looks like
Discussed before it happens, in a session where nothing is happening. Not proposed mid-activation, when you are least able to weigh it.
Specific: where, for how long, with what purpose. A hand on the upper back to support an orienting exercise is a different proposal from anything vaguer, and vagueness is itself a flag.
Revocable without explanation, at any moment, including halfway through, including after you already said yes twice. A practitioner who wants a reason is negotiating, and consent that has to be defended is not consent.
Recorded. It should appear in your notes and often in a separate written agreement.
What should end it
Touch that was not discussed first. Touch proposed while you are activated, distressed or crying. Any framing where declining means you are avoiding the work, not ready, or resisting. Any touch of the chest, groin, or buttocks. Anything happening with the door locked and nobody knowing you are there.
Also: a practitioner who responds to a question about their touch policy with irritation or a joke. You have learned what you needed to learn.
If something already happened
If a therapist touched you in a way that was not agreed, that is a boundary violation regardless of their intent and regardless of how kind they were otherwise. If they are licensed, their state board takes complaints, and you are allowed to make one without being certain it will succeed.
It is also worth telling a second therapist, if only so someone knowledgeable helps you sort out what happened. People carry these for years on the assumption that they must have misread it. Usually they did not.