Jurisdictional defect in an assessment may be raised in...

Jurisdictional defect in an assessment may be raised in collateral penalty proceedings where the assessment was made without a valid notice under section 143(2) from the jurisdictional Assessing Officer. An order made without jurisdiction is a nullity and may be challenged whenever enforcement or reliance is attempted, notwithstanding that the assessment has attained finality. Because the assessment was invalid and non est, the consequential penalty order was quashed.