Purpose: The purpose of this paper is to gain a better understanding of how national board administrators, more precisely, officials at the Finnish National Board of Education (FNBE) have perceived the primary influencing factors, or "regulators", of the national core curriculum reform and the success of the implementation. The alignment between the identified regulators was also explored. Design/methodology/approach: Altogether, 23 FNBE officials participated in this mixed methods study. Findings: The results showed that the officials perceived the core curriculum reform as a systemic entity: the reform was implemented using a top-down and bottom-up strategy, and several regulators were identified at different levels of the education system. The officials also viewed the implementation as successful, and identified more promoting than hindering factors in it. However, they emphasised regulators at the administrative level, whereas regulators at the district or national levels were less often identified. They also highlighted the importance of orchestrating collaboration in comparison with the other regulators. Practical implications: The results imply that in addition to considering separate determinants of reform success, it is important to pay attention to sufficient alignment between the regulators at different levels of the education system in order to better understand and promote the implementation of a large-scale reform. Originality/value: This study provides new knowledge on national board administrators' perspectives on what regulates the implementation of a large-scale curriculum reform.