The mission of the IFCC-EUBD is education on the use of biomarkers in diabetes, especially on improving quality of the assay of HbA1c. External Quality Assessment (Proficiency Testing) is a powerful tool to monitor the quality of tests in the medical laboratory. The EurA1c trial, organized yearly, investigates the performance of HbA1c assays across countries and manufacturers. EQA organisers of different countries use the same two samples either in their regular EQA program or stand-alone. Results of all countries are evaluated and presented in terms of performances per country and per manufacturer. The trial has Eurocentric roots but in the meantime also non-European countries are participating.