This paper aims to contribute knowledge about the influences of leaders' perceptions of digitalisation on arrangements for leading the expansion of access to and application of digital technologies in K-12 education. Supporting the digitalisation of K-12 education requires digital competence. School organisers' and school leaders' digital competence and perceptions of digitalisation contribute to how digital technologies are employed in schools. Survey and participant observations were used to investigate leaders' perceptions of digitalisation in K-12 education. The data were analysed using thematic analysis and theory of practice architecture. The results show that perceptions of digitalisation in K-12 education influence arrangements by allowing opportunities for enhanced quality in teaching and equality within and among schools. Further, collaborations between leaders, sharing ideas and experiences, and enhancing leadership are elements that contribute to the shaping of leaders' perceptions of digitalisation in schools. This paper contributes to the knowledge of leaders' perceptions of expanding the access to and application of digital technologies in schools.