A v. Migrationsverket, Case C-193/18, CJEU, 4 March 2021

Refusal to renew the residence permit for family reunification purposes as the identity of the applicant cannot be ascertained with certainty.

Convention implementing the Schengen Agreement of 14 June 1985 between the Governments of the States of the Benelux Economic Union, the Federal Republic of Germany and the French Republic concerning the gradual abolition of checks at common borders. 
 

 Article 25 of the Convention implementing the Schengen Agreement, concerning the abolition of controls at common borders, signed in Schengen (Luxembourg), must be interpreted in the sense that it does not preclude a legislation of a Member State that allows the release, extension or renewal of a residence permit for the purpose of family reunification, requested from the territory of that Member State by a third-country national who is the subject of an alert in the Schengen Information System for the purpose of refusing entry into the area Schengen and whose identity could not be proven with a valid travel document, when the interests of the Member State issuing the alert, previously consulted, have been taken into consideration and the residence permit is issued, extended or renewed only for "serious reasons "