The European Court of Justice (ECJ) will investigate tax residency rules in Portugal; this results from a referral by the European Commission which considers the Portuguese rules applicable to taxpayers who are no longer resident in the country to be incompatible with the right of free movement among EU states. Tax applies in cases where shares are exchanged, and when an asset and liability transfer is made to a company located abroad. The Commission considers this to be discriminatory, as it charges tax on individuals who leave Portugal on the value of their assets rather than on actual disposal, without regard to any future change in value. These measures could deter Portuguese tax residents from exercising their right to free movement.