I ran an online shop from Switzerland. Some years ago packages suddenly returned with the info I need to register with a packaging something company now. I had no idea what's going on, I didn't understand the concept and what they wanted. Apparently there were several companies I could register at pay a fee and it somehow became legal again, none of them looked real it looked like a lot of weird broken fake websites.

Germany was just a small market for us so we stopped shipping there.

I assume it's better and more clear these days and this probably makes it kinda easier in the long run. However it's a perfect example on how such things don't work if not done properly.