On 24 May 2023, Japan's House of Councilors (upper house of parliament) approved the pending income tax treaty with Azerbaijan. The treaty was approved by the House of Representatives (lower house) on 27 April. The treaty, signed 27 December 2022, will enter into force 30 days after the ratification instruments are exchanged and will apply from 1 January of the year following its entry into force. Once in force and effective, the treaty will replace the 1986 tax treaty between Japan and the former Soviet Union as it applies with respect to Azerbaijan and Japan.