The purpose of this contribution is to highlight the impact of formal credit on both the turnover and the formalization of informal production units (IPUs) in Comoros. Based on informal sector survey data, we analyse the impact using a method combining Propensity Score Matching (PSM) and the Coarsened Exact Matching (CEM) developed by Iacus et al. (2012). The results show that formal credit has a positive and significant impact on both the turnover and the formalisation of IPUs. The combination of the PSM with the CEM has considerably improved the quality of the matching.