US-headquartered firms now make up almost half of the 50 highest earning practices in the City of London, generating a record £4.27bn ($5.69bn) in the past year. Notwithstanding Brexit headwinds, the London legal press is awash with stories about intensifying competition between US and UK firms to land the biggest clients and hire the best lawyers, from high profile lateral moves to the “salary war” between US and Magic Circle firms.

Against this backdrop, it is worth considering some of the legal and cultural considerations faced by US firms when seeking to bolster their bench strength in London (if they already have a presence) or enter the London market. Here we focus on legal issues arising when hiring partners from UK firms, as well as some of the cultural differences in relation to partner duties and restrictions.