On 24 May 2006, a bill proposing amendments to the Netherlands Corporate Income Tax Act 1969 (CITA) was submitted to the Netherlands parliament. The proposal to amend the CITA was previously announced in the paper "Working on profit", issued on 29 April 2005. The effective date is proposed to be 1 January 2007. The aim of the bill is to improve the competitiveness of the Netherlands and to make its corporate income tax system EU-proof. This article describes the current rules and the most important changes proposed in the bill, including, among others, the introduction of the interest and patent boxes, restructuring the participation exemption, the treatment of interest, and broadening the tax base.