The first notice under section 143(2) issued to the assessee’s registered address was returned unserved and the Assessing Officer took no steps to effect service by any alternative mode. A fresh notice was issued more than sixteen months later, well beyond the statutory period prescribed under the Act. The Tribunal held that the Revenue failed to discharge its burden of proving valid service of notice within the prescribed time. As no valid notice under section 143(2) had been served within the limitation, the assessment was without jurisdiction and liable to be quashed. (AY. 2012-13).