There’s a lot of conflation and snobbery on this thread about being in a regulated profession and being a member of a professional body.
PSRBs are organisations that set the standards for, and regulate entry into, particular profession(s) and are authorised to accredit, approve or recognise specific programmes leading to the relevant professional qualification(s) - for which they may have a statutory or regulatory responsibility. This includes professions with protected titles. Law, financial, medical, teaching etc are regulated professions for obvious reasons.
A professional body is usually an organisation that oversees the activities of a particular profession and represents / lobbies the interests of its members. They serve a different purpose to statutory and regulatory bodies. It’s not always compulsory to be a member of one.
So for example, the SRA regulates solicitors, and the Law Society is their professional body. Within the legal profession certain titles are protected and certain legal activities are “reserved,” meaning they can only be undertaken by someone holding that title - so for example, rights of audience in a court.
Not all professions are regulated, and not all professional bodies have a royal charter. Being chartered means that you have reached
a certain level of professional expertise through professional development and experience for example, but it’s not always necessary to undertake that route. For example, being a member of the CIM if you’re in marketing or APM if you’re a project manager. However it can signal higher status and prestige within your industry so that’s why many will undertake the requirements to become so.
It’s perfectly possible to achieve in many professions chartered status or full membership of a professional body without necessarily having a degree if you have significant prior professional expertise and experience.