On 1 July 2016, the OECD-Council of Europe Convention on Mutual Administrative Assistance in Tax Matters as amended by the 2010 protocol entered into force for Bulgaria. The Convention, signed by Bulgaria on 26 October 2015, generally applies from 1 January 2017. However, it may apply for earlier periods between Bulgaria and another signatory if agreed to, and applies in relation to any period regarding criminal matters.