The gap between the rich and the rest is growing. Tax havens are at the heart of the inequality crisis, enabling corporations and wealthy individuals to dodge paying their fair share of tax. This prevents states from funding vital public services and combating poverty and inequality, with especially damaging effects for developing countries. The UK heads the world's biggest financial secrecy network, spanning its Crown Dependencies and Overseas Territories and centred on the City of London - but this in fact provides an unparalleled opportunity to help end the era of tax havens. As the UK Prime Minister prepares to host the anti-corruption summit in May, this briefing paper outlines how tax havens fuel the inequality crisis which leaves poor countries without the funds they need, the UK's role in the global tax haven system, and what the government can do about it.