All upstream projects in the UK are governed by concessions. Licences are awarded in regular rounds with fixed fiscal terms. Over the years, the tax system has seen numerous changes. Most recently, lower oil prices and maturity of the UK Continental Shelf have played a decisive role in radical tax cuts. The UK now has one of the most competitive fiscal systems globally. Ring Fence Corporation Tax (RFCT) applies at the rate of 30%. In addition, a 10% Supplementary Charge (SC) applies to the adjusted RFCT profit. Additional deductions are available for RFCT and SC.The UK has also one of the most elaborate tax treatments of decommissioning costs in the world. Most of the legislation is already in place but the industry actively cooperates with the government to resolve remaining issues. Transferrable Tax History (TTH) has been the most important initiative recently. It will allow buyers with no tax history in the UKCS to secure relief on future decommissioning losses.