The objective of this research is to measure the perception that teachers had about their own performance when they were forced to carry out an Emergency Remote Teaching due to the COVID-19 pandemic. A questionnaire was provided to teachers of every educational stage in the Basque Country (Pre-school, Primary and Secondary Education, Professional Training and Higher Education) obtaining a total of 4,586 responses. The statistical analysis of the data shows that the greatest difficulties reported by educators are shortcomings in their training in digital skills, which has made them perceive more workload during the lockdown and negative emotions. Another finding is the existing digital divide between teachers based on their gender, age and type of school. A further worrying result is the lower technological competence in lower educational levels, which are the most vulnerable in remote teaching. These results invite us to reflect on the measures to be taken to improve equity, social justice and resilience of the educational system, which align with some of the Sustainable Development Goals.