This paper focusses on case marking in informal Namibian German (so called Namdeutsch). Whilst the use of nominative and accusative case is stable and similar to Standard German, there is a considerable amount of variation with regard to the dative case. This phenomenon is analysed in detail using corpus and questionnaire data. Multifactorial analyses reveal that several sociolinguistic and grammatical factors have a significant impact on the language use in this particular domain. Subsequently, the results are compared with other extraterritorial varieties of German and various similarities are found. This supports the idea that there are variety/language overarching principles at work.