Interaction is seen by many English language teachers and scholars as an essential part of face-to-face English language classrooms. Teachers require specific competencies to effectively use interaction as a tool for mediating and assisting learning. These can be referred to as classroom interactional competence (CIC). However, the situation created by the ongoing global COVID-19 pandemic which began in early 2020, and the recent advancement in technologies have led to teachers conducting synchronous online lessons through video-conferencing software. The online environment is distinctly different from the face-to-face classroom and teachers require new and additional skills to effectively utilise interaction online in real time. This exploratory study used an online mixed-method survey of 75 university level English language teachers who had engaged in synchronous online teaching due to COVID-19, to explore the competencies that teachers need to use interaction as a tool to mediate and assist language learning in synchronous online lessons. Teachers were found to require three competencies, in addition to their CIC -- technological competencies, online environment management competencies, and online teacher interactional competencies -- which together constitute e-CIC. The findings provide greater insights into the needs of teachers required to teach synchronously online and will be of interest to teachers and teacher educators.