The widespread replacement of gross receipt tax (GRT) with value-added tax (VAT) is an important phenomenon in the past half-century. Theory predicts that such tax reforms reduce vertical integration, increase production efficiency, and improve industrial structure. We exploit the tax reform that replaced GRT with VAT for service industries in China and find empirical evidence consistent with theoretical predictions. First, the tax reform increases the probability and intensity of outsourcing for both manufacturing and service firms. The increase is larger for industries more heavily reliant on treated intermediate industries for production and for firms with higher capital–labor intensity. Second, the reform increases total factor productivity and labor productivity. Third, the reform affects industry structure by boosting sales and promoting the employment of treated service industries.