(1) Subject to the provisions of paragraph (2) of Article 19, pensions and other similar remuneration paid to a resident of a Contracting State in consideration of past employment shall be taxable only in that State.
(2) The provisions of paragraph (1) shall not apply if the beneficial owner of the income is not subject to taxation with respect to such income in the State of which he is a resident under its domestic laws. In such case, the income shall be taxed only in the State in which it arises.
(3) Notwithstanding the provisions of paragraph (1) of this Article, pensions and other similar remuneration derived under the social security laws of a Contracting State shall be taxable only in that State.
(4) Where a resident of a Contracting State becomes a resident of the other Contracting State, then the income received as compensation on termination of his employment in the first-mentioned Contracting State or any lump sum amount of a similar nature, shall be taxable only in the first-mentioned Contracting State.