Situation
A shop that unpacks stock and throws away the outer packaging
The situation
A business receives stock wrapped on pallets or in outer cartons, strips that packaging off and bins it, then sells the goods on. Its own packaging is plain and it sells only at home.
What appears to apply
Producer is the word the rules use for whoever first puts packaging onto a country's market. It is worked out country by country, so one business can be a producer in several countries at once. There are five ways to become one. Two cover selling packaged goods at home. Two cover sending packaged goods straight to customers in another EU country. The fifth catches a business that unpacks goods without being the one who uses them, unless somebody earlier in the chain already counts as the producer.
Source: Regulation (EU) 2025/40, Art. 3(1), point (15) — read from this source on
The two about sending goods to customers in another country decide whether a representative is needed there. The fifth, about unpacking, is the one most often missed.