[djs55]

In the past I worked for a UK company from the UK which was owned by a US parent, where employees in the UK were granted options in the US company under the HMRC Enterprise Management Incentives (EMI) scheme: https://www.gov.uk/tax-employee-share-schemes/enterprise-man... . I think without the scheme if I had exercised an option (whether to hold onto the share or to sell immediately) then I would have owed income tax on the difference between the strike price and the current value i.e. the discount my employer effectively gave me. I think I would have owed the tax even if I was forbidden to sell the stock (e.g. if the company had stayed private). With EMI there was no income tax on exercise and I only owed capital gains tax when I eventually sold the stock.