There are various regulating bodies that most Ts are registered with that follow ethical frameworks and that require a certain amount of training and clinical experience to become a member. There's not much understanding of that system amongst the general public (potential clients) though, and it's pretty terrifying that anyone can go out there and call themselves a counsellor or psychotherapist.

My T, like most, is BACP (British Association for Counselling and Psychotherapy) registered. I would absolutely not see a T who isn't, but also I wouldn't say it's a guarantee of a good T. Unfortunately there are still plenty of s***ty ones, same as in the US!