Virtually all upstream projects in Ukraine operate under the concession regime. Production Sharing Contracts (PSCs) were introduced to attract foreign investment primarily in offshore licences. Only a couple of PSCs still exist and none of them contains any producing fields. In 2013, a subsoil use tax replaced royalty. Its current rates range between 14% and 29% for liquids and between 6% and 12% for gas. Corporate income tax has been unchanged at 18% since 2014. Currently, Ukraine pursues an open door policy for licence awards but the government is considering regular licensing rounds.