Robust screening algorithms to improve diagnostic accuracy and minimise false positives are required.AIMWe conducted a nationwide, population-based serosurvey to estimate HBV prevalence in Belgium by using HBsAg alone or combined with hepatitis B core antibody (anti-HBc) positivity as infection criterion.METHODSWe analysed HBsAg and anti-HBc in a total of 4,955 left-over serum samples from severe acute respiratory syndrome coronavirus 2 sero-epidemiology studies in 2020. This evidence concerns the gene KRT88P and infection.