This report is part of the OECD Tax Policy Reviews publication series. The Reviews are intended to provide independent, comprehensive and comparative assessments of OECD member and non-member countries' tax systems or zoom in on a specific tax policy topic. This report provides an in-depth assessment of Colombia's tax expenditure reporting practices and makes specific recommendations as to how the measurement of tax expenditures and their reporting can be improved. In particular, the review introduces a benchmark for the corporate and personal income tax and the value-added tax and calculates revenue forgone from income tax expenditures.