The Monegasque Government has introduced a new regime (Law 1,381 and Ministerial order n° 2011-444) which will apply to every legal entity owning real estate in the Principality of Monaco.
The new provisions require every legal entity owning real estate to disclose any change (or non-change) in the beneficial ownership of the entity annually by filing a return. The first return under the new regime should be filed with the Monaco Tax Office between 1 July and 30 September 2012 for the period 1 July 2011 to 30 June 2012. All filings must be made through an authorized tax representative. Please note that failure to appoint a Monegasque tax representative before 30 June 2012 will result in the payment of a 1,5% penalty assessed on the fair market value of the property.
Source: http://gordonblair.com/new-legal-obligation-for-entities-owning-real-estate-in-monaco/