Where an employed or self-employed person who is a national of one Member State becomes subject to the legislation of another Member State, the competent institution in respect of pensions of the latter Member State shall, using all the means at its disposal and at the time of registration of the person concerned, forward to the body designated by the competent authority of that same Member State, all information relating to the identification of the person concerned and the name of the said competent institution and the insurance number allotted by the latter.