Little is known about the non-use of unemployment benefits (for individuals who are eligible). Studies in the USA, England and Canada show that in these countries, between 30% and 50% of eligible unemployed individuals do not claim their benefits. Work on the FH-DADS panel has shown similar rates for France (Blasco et Fontaine, 2017). This behavior, often ignored in empirical and theoretical studies, can have important consequences on costs and on the efficiency of unemployment benefit systems. We will try, using the FH-DADS panel, to analyze the deep reasons: Administrative complexity of claiming unemployment benefits? Lack of information? Or is it just a fast way back to employment which lessens the need for claiming benefits?