The tax wedge shall express the share of taxes and social security contributions in total labour costs in a given state. The Czech tax wedge, published by the OECD, expresses this relationship correctly only because we do not have mandatory private pension savings, significant occupational pension schemes or similar products. The annual OECD publication “Taxing Wages” ignores non-tax compulsory payment wedges, even though the OECD calculates and reports them on its website. From the widely published data in Taxing Wages, it is not possible to generate recommendations to reduce the tax burden of labour or merely the rate of employer social security contributions in Czechia. Various welfare regimes use different forms of social security funding with an automatic impact on the structure of labour costs. In Czechia, the rationalization of personal income tax and social security contributions can be relatively straightforward, resulting, in particular, in integrating the personal income tax and the employee social security contributions. This paper constitutes an international comparison and analysis of the labour cost structure, aiming at correcting or confirming the conclusions and recommendations of the OECD and the EC for Czechia.