This corpus contains essays written in official HABE exams for assessing student's knowledge of the Basque language. We have collected 120 essays in each of the B1, B2, C1 and C2 CEFR levels. The essays have been evaluated by reviewers and we have included the qualifications in all the evaluated criteria. The corpus includes essays that have passed the test as well as essays that have not. The information published here is very useful for error analysis as well as studying different linguistic phenomena at every level. The corpus has been preprocessed, cleaned, formatted and anonymized at the Ixa Group (UPV/EHU).