Court of Justice (Sixth Chamber) 25 October 2018, C-451/17 („Walltopia“ AD v Direktor na Teritorialna direktsia na Natsionalnata agentsia za prihodite – Veliko Tarnovo.)

JUDGMENT OF THE COURT (Sixth Chamber) 25 October 2018 ( *1 ) (Reference for a preliminary ruling — Social security — Regulation (EC) No 883/2004 — Article 12(1) — Regulation (EC) No 987/2009 — Article 14(1) — Posted workers — Legislation applicable — A1 certificate — Whether the employee is subject to the legislation of the Member State in which his employer is established — Conditions) In Case