Venture capital investors in the US typically only invest in the UK if a startup changes its corporate structure, establishing a US parent company that's incorporated in Delaware. However, this trend seems to be changing as there are real tax advantages to investing directly into a UK startup.
A Delaware flip today would potentially subject more of a company’s global profits to US corporate tax rates that are among the world’s highest, often exceeding 40 per cent in combined federal and state taxation. The UK corporate tax rate, meanwhile, is now 20 per cent and going down. Such national tax disparities are driving the popularity of “inversions” like the Pfizer deal. These are corporate transactions structured to ensure that the merger of a US company with a non-US firm results in the parent company being based in a lower-tax jurisdiction.