The article looks at how UK courts have dealt with the government's challenges to transactions undertaken to avoid tax. First it gives some background, including the US precedent regarding purposive interpretation, the Duke of Westminster principle, sham transactions, and the Ramsay principle. It then examines the post-Ramsay law as reflected in six court decisions in 2000 and 2001, and concludes by summarizing the current status of the law on tax avoidance transactions.