Do I have to declare the shipping box and filling too?

Yes, when you ship directly to end users in Spain. The PPWR defines the producer of transport packaging separately (Article 3(1)(15)(c)): a manufacturer, importer or distributor established outside Spain that makes it available for the first time directly to end users there. MITECO's note of 13 August 2026 works the case of a Portuguese company selling online to Spanish consumers: it is the producer in Spain of the sales packaging and of the transport packaging, and must appoint a Spanish authorised representative. If a fulfilment service ships for you, check who it treats as producer of the outer box; Zalando, for example, says it is the producer of the shipping packaging for its fulfilment partners. RRegulation (EU) 2025/40 (PPW+2