Invisible architects of offshore finance: The Big Four in Luxembourg

Abstract This article reconstructs the historical rise of the Big Four accounting firms as central actors in Luxembourg’s offshore financial centre. Moving beyond bank- and law-centric narratives, it traces how international audit networks embedded themselves in a small national market from the 1970s onward through alliances with leading local fiduciaries, integration into the expanding investment fund industry, and participation in regulatory and consultative arenas. Drawing on interviews, professional data, and institutional records, the study shows how these firms shifted from marginal service providers to key architects of tax structuring, fund governance, and financial legislation. Their dominance in fund auditing, growing role in tax and advisory work, and organizational model reshaped professional hierarchies, including the legal sector. The Luxembourg case highlights how global professional service firms act as intermediaries between states and mobile capital, making them structural components of contemporary offshore finance rather than merely technical advisers.