This paper analyzes the implications of foreign firm ownership and international profit shifting through thin capitalization for corporate tax policy. We consider a model of interjurisdictional tax competition where the corporate tax serves as a backstop to the personal income tax, interest on debt is deductible from the corporate tax base and multinational firms may shift profit across countries through thin capitalization. We show that the problem of thin capitalization induces countries to reduce their corporate tax rates below the personal income tax rate and to broaden their tax bases. Moreover, foreign firm ownership leads to a reduction in corporate tax rates. We also show that there is scope for welfare enhancing tax coordination in our model. In the presence of both foreign firm ownership and thin capitalization, countries gain from a coordinated increase in corporate tax rates or from a coordinated broadening of the tax base.