(1) Subject to Articles 14 and 16 to 20, this Article shall apply to determine a person’s entitlement to retirement pension, including any increase for dependants, under the legislation of any part of either Party.
(2) In accordance with Article 12, the competent authority of any part of either Party shall determine—
(a)the amount of the theoretical pension which would be payable if all the relevant insurance periods completed under the legislation of both Parties had been completed under its own legislation;
(b)the proportion of such theoretical pension which bears the same relation to the whole as the total of the insurance periods completed under the legislation of that part of either Party bears to the total of all the relevant insurance periods completed under the legislation of both Parties.
The proportionate amount thus calculated shall be the rate of pension actually payable by the competent authority.
(3) For the purpose of the calculation in paragraph (2), where all the insurance periods completed by any person under the legislation of—
(i)Great Britain, Northern Ireland and the Isle of Man amount to less than one reckonable year or, as the case may be, one qualifying year, or relate only to periods before 6 April 1975 and in aggregate amount to less than fifty weeks, or
(ii)Jersey amount to less than an annual contribution factor of 1.00, or
(iii)Guernsey amount to less than fifty weeks,
those periods shall be treated in accordance with paragraph (4) or (5).
(4) Insurance periods under paragraph (3) shall be treated as follows—
(a)as if they had been completed under the legislation of any part of the United Kingdom under which a pension is, or if such periods are taken into account, would be, payable, or
(b)where a pension is, or would be, payable under the legislation of two or more parts of the United Kingdom as if they had been completed under the legislation of that part which, at the date on which entitlement first arose or arises, is paying, or would pay, the greater, or greatest amount.
(5) Where no pension is, or would be, payable under paragraph (4), insurance periods under paragraph (3) shall be treated as if they had been completed under the legislation of Jamaica.
(6) Where all the insurance periods completed by a person under the legislation of Jamaica amount to less than fifty-two weeks, those periods shall be treated as if they had been completed under the legislation of the United Kingdom in accordance with paragraph (4).
(7) Any increase of benefit payable under the legislation of Great Britain, Northern Ireland or the Isle of Man because of deferred retirement or deferred entitlement, shall be based on the amount of the pro-rata pension calculated in accordance with this Article.