GST classification of fertilisers clarifies concessional rate applies to potassic and other fertilisers including supply for manufacture. Mineral and chemical fertilisers, potassic and other types, are classified in Schedule 1 at a concessional GST @ 5% when goods are used as fertilisers; the classification expressly includes fertilisers supplied for use in the manufacture of other fertilisers per Circular No. 54/28/2018 GST, as inserted by notification no. 18/2017 Central Tax (rate).