The Bill will empower the Assembly to set the corporation tax rate, which could be a different rate from the rest of the UK, over most trading profits in a new Northern Ireland corporation tax regime. It does not include non-trading profits such as income from property. Power over the corporation tax base, including reliefs and allowances, will remain with the UK parliament.

Profits from some trades, including lending and investing activities; asset management; finance leasing; long-term insurance (including life insurance) and reinsurance activities of both general and life insurance, will remain in the UK main regime, as will the taxation of oil and gas.