BHP Billiton will include an income tax expense of $US1.8 billion in its half year accounts due to a cut to corporate income tax rates in the US.
The US federal corporate tax rate has dropped from 35 per cent to 21 per cent under President Donald Trump's tax changes, and BHP said that will lead to a $US898 million reduction in the value of the company's deferred taxes.
The miner will also recognise a US$834 million non-cash impairment of foreign tax credits.
Both items will be reported as exceptional items in BHP's accounts, which are to be published on February 20.
BHP said the tax reforms will have a positive impact on its profits in the longer term, mainly due to the reduced corporate tax rate.
BHP made a net profit of $US3.2 billion in the first half of the 2016/17 financial year.