Whereas in Germany migration is often associated with Islam, this contribution focuses on Catholic migrants from the perspective of canon law. In 2023, the percentage of Catholics with foreign citizenship rose to 16.5% of the total number of Catholics in Germany, and even to 36.7% in the Archdiocese of Hamburg. The religious traditions of the country of origin and the country of destination often differ in terms of history, language, liturgy, spirituality and the forms of religious practice. The Catholic Church has established organisational structures in most parts of the world. Wherever Catholic believers migrate to, they will find Catholic pastoral structures. Therefore, the question is not whether they change their church as a result of migration but rather which subdivision they will be assigned to and which entity will be responsible for their pastoral care. The fundamental and comprehensive legal document is still the 2004 instruction 'Erga migrantes caritas Christi'. Stronger migration movements give rise to specific structures, which will be briefly outlined in this presentation: Missio sine cura animarum, Missio cum cura animarum, quasi-parish, personal parish, etc. On the one hand, legal arrangements provide space for preserving one's own tradition, but on the other hand, migration makes these arrangements change and transform. This results in a reciprocal effect between canon law and migration. However, migration not only affects internal structures of the Catholic Church but also leads to a reshaping of relations with non-Catholic churches and religious communities.