Ireland’s concession regime is relatively simple. The main element is a Petroleum Production Tax (PPT) and corporate income tax. The PPT replaced the Profit Resource Rent Tax in 2014 and is calculated on a field's net income at a rate that is determined by an R-factor ratio. It is also deductible for calculating corporate income tax. There are also several rental fees and indirect taxes. Corporate income tax is ring-fenced within upstream activities at the company level.