UPS Germany maintains a notification and complaint procedure in accordance with the Lieferkettensorgfaltspflichtengesetz (LkSG).
If you are seeking contact with UPS, even anonymously, about potential violations, you have the following options:
UPS Ethics Hotline: +49 (0) 800 - 6648862
Online form for submission (EthicsPoint)
Or you can write to:
United Parcel Service Deutschland S.a.r.l. &Co.OHG
Abteilung Compliance und Ethics
Görlitzer Str. 1
41456 Neuss