This application note aims at analyzing the steps required to migrate from an existing STM8L-based design to any one of the other microcontroller types in the fast-growing STM8L family. This application note groups all the most important information and provides a list of the fundamental aspects. The information included in this document can also be extremely useful in a first STM8 design. Studying the issues in this phase can allow the user to adapt from the beginning his design to any future requirement. To benefit fully from the information in this application note, the user should be familiar with the STM8L microcontroller family.