Most licences in Kazakhstan are governed by Concession terms. The main projects (Kashagan, Karachaganak and Tengiz) and a number of smaller projects operate under the PSC/special terms. However, a law was passed in 2010 which means PSCs can no longer be awarded for new licences. Standard Concession terms include five major taxes - Mineral Extraction Tax (MET), rent tax on the export of crude oil, excess profits tax (EPT), oil export customs duty (ECD) and corporate income tax. In December 2017, Kazakhstan adopted a new Tax Code, effective January 2018, which introduced optional alternative fiscal terms - Alternative Subsoil Tax (AST) for offshore and deep onshore fields in the Concession regime, that aims to incentivize investment in shelf exploration. Fields that opt for AST will be exempt from MET, rent tax on export, EPT and reimbursement of historical state costs. The AST is levied on profit at a rate linked to the oil price.