Empirical evidence on the degree of business-tax shifting is rare. It remains open to which extent the tax burden is shifted, whether there are differences for tax increases and decreases, or whether there exists some treatment heterogeneity. Using a large administrative panel data set, we exploit the regional variation of the German business-income taxation and find that 65% to at most 93% is shifted to labour through real wage adjustments. We find that business taxation increases wage inequality significantly. Workers in a weak labour-market position bear the highest part of business taxation. The incidence effect of tax reliefs is significantly higher than that of tax increases. Therefore, reducing business taxes might, surprisingly, effectively reduce inequality.