The individual at the underwriting box within Lloyd's of London with principal authority to accept insurance and reinsurance risk on behalf of the members of a syndicate. The active underwriter is responsible for setting underwriting strategy, making binding decisions on risks presented by Lloyd's brokers, managing the syndicate's portfolio, and ensuring that underwriting activities align with the syndicate's business plan and risk appetite. This role requires deep technical expertise, market knowledge, and strong decision-making capabilities as the active underwriter's choices directly impact syndicate performance and member returns.