Power and fertiliser contractors
Thermal and fertiliser operations bring contractors working to audited terms with purchase orders and gate registers. An invoice carrying both GSTINs, HSN codes, line-wise tax and the PO reference is what clears, and the challan reconciles against their store at month end.
Township retail alongside
The colonies around the plants bring steady counter trade in hardware, sanitaryware, paint and electrical. That is a thirty-second cash bill rather than a referenced invoice, and running both from one system is what stops a shop keeping two records that disagree.
Long payment cycles
A contractor working for a large public operation is paid when their process releases it, which is deliberate rather than quick. Ageing rather than totals tells you where you stand, and a limit per contractor keeps exposure inside what the shop can carry.