BP expects its future US after-tax earnings to be positively impacted by the recently-enacted changes to US corporate taxes, largely due to the reduction of the US federal corporate income tax rate from 35% to 21% (effective 1 January 2018). The ultimate impact of the change in the US corporate income tax rate is subject to a number of complex provisions in the legislation which BP is reviewing. The lowering of the US corporate income tax rate to 21% requires revaluation of BP's US deferred tax assets and liabilities. The current estimated impact of this will be a one-off non-cash charge to the Group income statement of around $1.5 billion that will impact BP's fourth quarter 2017 results.