CCM13110 - Discovery Decisions: Time limit for S20(4) decision

S20(5) says that no decision may be made

1. unless it is too late to enquire into the entitlement, or joint entitlement, under section 19, or
2. after the period of five years beginning with the end of the tax year to which the conclusive decision relates.

This means that if you can still open a S19 enquiry then you must do so. However, S20(5)(b) places an over-riding time limit on the discovery decision. Such a decision cannot be made after 5 years from the end of the tax year to which the conclusive decision relates. Therefore, if the conclusive decision was for 2003/2004 a S20(4) discovery decision cannot be made after 5 April 2009.