Artikel 3

1. In cases arising under Articles 7 to 11 of the Convention, the competent authority or competent institution of the Party whose legislation is being applied will issue to the insured person or to his employer, on application, a certificate showing that the insured person remains liable for contributions under that legislation.
2. Where the last sentence of Article 10(2) or Article 13 of the Convention applies and the employer has made an application to the competent authority or competent institution whose legislation is being applied for an extension of the period of liability, the application will be dealt with by correspondence between the competent authorities or competent institutions of the two Parties.