To set up an investment advisor and arranger in the UK, one must first decide whether to establish as a limited company or limited liability partnership (LLP). It is important to seek tax advice on the appropriate structure. If the activities require authorization from the Financial Conduct Authority (FCA), the firm must apply for authorization and approval of individuals in controlled functions. The application process takes 4-6 months and requires demonstrating adequate resources, appropriate systems and controls, approved staff, and necessary qualifications. Setting up costs can include incorporation, legal agreements, FCA application and fees, compliance systems, and ongoing accounting and regulatory reporting requirements.