(1) This Convention shall apply to taxes on income imposed on behalf of a Contracting State or of its political or administrative subdivisions or local authorities, irrespective of the manner in which they are levied.
(2) There shall be regarded as taxes on income all taxes imposed on total income, or on elements of income, including taxes on gains from the alienation of movable or immovable property, taxes on the total amounts of wages or salaries paid by enterprises, as well as taxes on capital appreciation.
(3) The existing taxes to which the Convention shall apply are, in particular:
- (a) in the case of Portugal:
- (i) the personal income tax (imposto sobre o rendimento das pessoas singulares-IRS);
- (ii) the corporate income tax (imposto sobre o rendimento das pessoas colectivas-IRC); and
- (iii) the local surtax on corporate income tax (derrama);
- (hereinafter referred to as "Portuguese tax");
- (b) in the case of the Slovak Republic:
- (i) the tax on income of individuals;
- (ii) the tax on income of legal entities;
- (hereinafter referred to as "Slovak tax").
(4) The Convention shall apply also to any identical or substantially similar taxes which are imposed after the date of signature of this Convention in addition to, or in place of, the existing taxes. The competent authorities of the Contracting States shall notify each other of any substantial changes which have been made in their respective taxation laws.