In recent years, ion traps have developed from a topic of fundamental research into a versatile tool for a wide range of research topics and quantum technologies. With the ability to isolate the ions from their environment, atomic and molecular ions can now be studied in unparalleled detail. This capability has led to important scientific progress in fundamental research, such as the measurement of cold collisions between trapped ions and cold atomic or molecular particles, the study of the interaction of light with trapped ions, or mass measurements with ultra-high precision. Beyond purely fundamental research, ion traps have become indispensable for many applications and technologies. Trapped ions are currently the most promising implementation of quantum information processing devices where many essential building blocks have been developed in recent years; magnetic field sensing with high sensitivity has been demonstrated and some of today’s best atomic clocks are based on atomic ions. These applications have the potential to revolutionise many aspects of our daily life. The aim of this Action is to enhance the current applications of trapped ions by supporting Europe-wide collaborations and knowledge exchange, and to allow these technologies to be taken a step further towards their commercialisation.