Even if you don't have to be registered for a certain type of complementary therapy, your clients will want to see evidence that you're fully trained and competent to practice. You can demonstrate this by taking a course that is approved or recognised by a professional body.
Whether you register voluntarily with a regulatory body or not, it is strongly recommended that you also belong to a professional association. It demonstrates to potential clients that you are professional, qualified and committed to the profession and follow a code of conduct and ethics within your practice. Most professional associations will offer many benefits such as free directory listings on their websites, access to educational resources, free magazines, discounts on products, and professional liability insurance, which is an absolute must.