This working paper examines the economic role of airport transfer services — scheduled rail, coach, licensed taxi and private-hire transfers, and app-based ride-hailing — in shaping regional tourism, using London Gatwick Airport as a case study. Gatwick is selected for its scale as the United Kingdom's second-busiest airport (43.2 million passengers in 2024), its exceptional rail connectivity and highest-in-the-UK public-transport mode share, and the binding surface-access conditions attached to its Northern Runway expansion. Adopting a qualitative evidence-synthesis design, the paper draws on published statistics from the Civil Aviation Authority, the Office for National Statistics, VisitBritain, the Office of Rail and Road, the Chartered Institute of Logistics and Transport, UK Parliament briefings, and Gatwick's corporate reporting. It applies the direct–indirect–induced–catalytic framework of airport economic impact to transfer services and compares surface-access modes across cost, convenience, luggage suitability, reliability and carbon intensity. The analysis finds well-evidenced links between surface-access quality and airport competitiveness, but also finds that the isolated causal contribution of transfer services to regional tourism is not yet robustly quantified — and sets out a research agenda to address this gap. Intended for researchers, policymakers, tourism professionals and students.