The paper looks at changes in tax regulations and social benefits in Poland from 2006 to 2014 and evaluates their impact on the taxation of labor in the country depending on the type of family. By simulating a regulatory equivalence scale the paper shows that changes in tax and benefit rules were the most beneficial for large families with low income from employment. The average taxation of labor income in low-income families with two parents and three children decreased by almost 13 percentage points in the studied period, while the value of the regulatory equivalence scale for such families increased from 1.28 to 1.40. However, the values of the scale are still noticeably lower than those of the OECD scale. The impact of regulatory changes on the progressivity of the tax-and-benefit system and stronger dependence of labor taxation on the number of children were highlighted in the discussion of the results.