Purpose: The COVID-19 pandemic is a unique event that forced K-12 schools to rethink the delivery of instruction to protect the well-being of school system stakeholders. Teachers, school administrators and parents had to adapt to and embrace new ways of teaching and learning by utilizing available technology. The purpose of this study is to examine the challenges encountered by in-service teachers when moving from face-to-face to online teaching. Design/methodology/approach: This study utilized a qualitative phenomenological research methodology to examine Ecuadorian and Uruguayan teachers' perceptions and experiences transitioning from face-to-face to online teaching during the COVID-19 pandemic. This comparative study used convenience sampling to include 12 K-12 teachers from Ecuador and Uruguay. Findings: The results of this study produced two themes that evidenced the demands placed on educators. The first theme was job demands, relating to teachers' perceptions about workload, preparation time and curriculum issues. The second theme related to available support provided by the school administrators and technology issues faced by teachers and students. Even though the teachers demonstrated adaptability for educating students during the pandemic, the experiences from both countries should be considered by teacher training programs and in post-graduate professional development. Originality/value: This article examined how COVID-19 affected teachers in Uruguay and Ecuador. Data analysis documented the challenges encountered by teachers transitioning to online learning during the pandemic. The findings inform a larger audience about the needs of teachers working online.