All financial advisers have to earn a living and they may offer their services in exchange for fees or commission or sometimes both. Fees usually mean that you pay a fixed amount to the adviser up front, depending on how complicated your advice needs are, or sometimes an hourly rate. Commission usually means you don't pay the adviser any money directly yourself. Instead, the provider of any products you buy pays commission to the adviser and deducts the cost from the value of your product. The cost of the commission is taken into account in the charges you pay under your product, together with the other costs of setting up and operating.
Tax is another issue.
VAT is payable on fees, but not on commission payments. However, your adviser may give back to you part of the commission he receives. If so, you may be liable to income tax on the amount you get back. The FSA keeps a list called the Central Register, which means you can check up on a firm before doing business with it. The Central Register is available on the FSA website.