Starting 1 January 2007 tax residency for the Russian individual income tax purposes will be defined as 183 or more days spent during consequent 12 months. Short term (less than 6 months) treatment or study outside Russia will not terminate the period of stay in Russia. The new rules were introduced by the Federal Law No 137-FZ, dated 27 July 2006. Currently the 183 days period is calculated in a calendar year. Therefore, starting 2007 the new rules should be considered while planning periods of assignment of personnel to/from Russia for work and the relevant individual income tax planning.