The profession of Counselling & Psychotherapy is not regulated in the UK, and the titles ‘counsellor’ and ‘psychotherapist’ are not protected. As a result, it would not be unlawful for anyone without any training or qualifications to call themselves a therapist and start working with clients. 

NCPS (National Counselling & Psychotherapy Society), BACP (British Association of Counselling & Psychotherapy) and UKCP (UK Council for Psychotherapy) are three of the largest professional organisations offering accreditation to trained therapists and training programs. There are several more. Contrary to popular belief, these are not regulatory bodies; they are voluntary membership organisations. 

Although it is optional to register and get accredited with professional bodies like these, many therapists choose to, as a way to demonstrate that their training and experience meet certain criteria. 

I am a Senior Accredited Member of the National Counselling & Psychotherapy Society (NCPS), and part of their Accredited Register by the Professional Standards Authority.