The objective of the present investigation, consists in determining the elasticities of tax collection of the small municipalities in Colombia, in order to prove that there are faults in the municipal tax system. For it, a classification of the 1124 municipalities is carried out of Colombia, in the period 2003-2014, based on the cluster analysis technique, K-medium method and calculation of the tax collection elasticity, estimated by panel data model. As a result of the study, it is concluded that, the elasticity of tax revenues based on economic activity in small municipalities in Colombia, evidences a trend of inelastic tax collection, in relation to defined estimation variables, such as: consumption of drinking water, electric power, national transfers, fiscal efficiency, expenses of individuals and target population. At the same time, a low fiscal efficiency could be determined in the analyzed municipalities, framed within a criterion of fiscal laziness and accommodation of local autonomy to national transfers.