Service of notice: prescribed delivery modes and deemed service rules determine when statutory communications are treated as served. Section 169 prescribes modes for serving decisions, orders, summonses, notices or other communications under the Act - personal delivery (including to authorised representatives, advocates, tax practitioners, employees or adult family members), registered/speed post or courier with acknowledgment, e mail provided at registration, availability on the common portal, publication in a local newspaper, or, if impracticable, affixation at the last known place of business/residence or on the issuing office's notice board. It further provides that such communications are deemed served when tendered, published or affixed, and that items sent by registered or speed post are deemed received after the normal transit period unless disproved.