It's the same here in the U.S, bring your own or buy their plastic reusable ones. The locations I've been too sometimes had spare boxes you could use, but that was pretty rare.
Aldi has no problem with you reshuffling the stock on the shelf to create an 'empty' box out of two partially filled ones. I've gotten really good at this.
When you think about it, it also keeps the shelves a bit more organized when people are walking away with the cardboard that would normally have to be recovered and packed up by the employees.
