The topic raised in this thesis is the impact of the principle of consistency and taxpaying capacity by including the passenger land transportation service within the “detracciones” system. This is due to the fact that although the original purpose of the “detracciones” (withholding tax) regime is to collect the General Sales Tax in advance through the customer’s payment of the amount withheld as a deposit into a special supplier’s bank account, operations have been included without a differentiated treatment with the course of time. This is the case of the passenger land transportation service despite not being subject to taxes (because of being exempt). Likewise, the assessment of the “detracciones” amount is made based on the axles of the vehicles that pass through the toll gates at the national level, whereas for the rest of the operations, the Tax Liabilities of the ...