(1) Each of the Contracting States shall notify the other, through diplomatic channels, of the completion of the procedures required by its law for the bringing into force of this Convention. This Convention shall enter into force on the date of the later of these notifications and shall thereupon have effect:
(a) in the United Kingdom:
(i) in respect of taxes withheld at source, to income derived on or after 1st January in the calendar year next following that in which this Convention enters into force;
(ii) subject to sub-paragraph (a)(i) above, in respect of income tax and capital gains tax, for any year of assessment beginning on or after 6th April in the calendar year next following that in which this Convention enters into force;
(iii) in respect of corporation tax, for any financial year beginning on or after 1st April in the calendar year next following that in which this Convention enters into force;
(b) in Poland:
(i) in respect of taxes withheld at source, to income derived on or after 1st January in the calendar year next following the year in which the Convention enters into force;
(ii) in respect of other taxes on income and capital gains, to such taxes chargeable for any taxable year beginning on or after 1st January in the calendar year next following the year in which the Convention enters into force.
(2) The Convention between the Government of the United Kingdom of Great Britain and Northern Ireland and the Government of the Polish People’s Republic for the avoidance of double taxation with respect to taxes on income and capital gains signed at London on 16th December 1976 shall terminate and cease to be effective from the date upon which this Convention has effect in respect of the taxes to which this Convention applies in accordance with the provisions of paragraph (1) of this Article.