Independent personal services: residence taxation may be shared with source state when fixed base or prolonged presence exists. Income from independent personal services by a resident is taxable only in the resident State except where the taxpayer has a fixed base in the other State - then only income attributable to that fixed base may be taxed there - or where the taxpayer's presence in the other State meets the treaty's aggregate presence threshold, in which case only income from activities performed there may be taxed by that State. The treaty lists examples of professional services to which these rules apply.