Article 14 3.

However, in respect of invalidity, old age and survivors' benefits, the person concerned may join the voluntary or optional continued insurance scheme of a Member State, even if he/she is compulsorily subject to the legislation of another Member State, provided that he/she has been subject, at some stage in his/her career, to the legislation of the first Member State because or as a consequence of an activity as an employed or self-employed person and if such overlapping is explicitly or implicitly allowed under the legislation of the first Member State.