Whilst the U.K. tax treatment of management fees relating to, and performance fees arising from, fund arrangements has been the subject of debate for some time, the recent introduction of new U.K. legislation has brought the issue into sharper focus in the United Kingdom. Accordingly, hedge fund personnel operating within the United Kingdom may be affected by the new legislation and thus subject to increased taxation on fees and compensation earned with respect to their investment management activities. In a guest article, the first in a two-part series, Sidley Austin partner Will Smith discusses the background and enactment of the new legislation known as the “disguised fee rules” and provides a summary of their technical application. The second article in the series will detail exceptions to the application of the disguised fee rules and discuss certain practical consequences which may arise under the new legislation. For additional insight from Smith, see “Potential Impact on US Hedge Fund Managers of the Reform of the UK Tax Regime Relating to Partnerships and Limited Liability Partnerships,” Hedge Fund Law Report, Vol. 7, No. 10 (Mar. 13, 2014). For insight from Smith’s partner Leonard Ng, see “Sidley Austin, Ivaldi Capital and Advise Technologies Share Lessons for U.K. Hedge Fund Managers from the January 2015 AIFMD Annex IV Filing,” Hedge Fund Law Report, Vol. 8, No. 12 (Mar. 27, 2015). For insight from Sidley more generally, see “Sidley Partners Discuss Evolving Hedge Fund Fee Structures, Seed Deal Terms, Single Investor Hedge Funds, Risk Aggregators, Expense Allocations, Co-Investments and Fund Liquidity (Part One of Two),” Hedge Fund Law Report, Vol. 7, No. 36 (Sep. 25, 2014).