Post-sale discounts: credit notes that don't alter transaction value don't require reversal of input tax credit; inducement rules vary. Where suppliers issue financial/commercial credit notes without reducing the original transaction value, the supplier's tax liability remains unchanged and the recipient need not reverse Input Tax Credit. Post sale discounts by a manufacturer to a dealer are not consideration for the dealer's supply when sales are independent principal to principal transactions, but are includible in consideration where the manufacturer has an agreement with the end customer and enables the dealer to supply at the agreed discounted price. Discounts that merely reduce the dealer's sale price are not taxable as separate services unless a distinct promotional service with specified consideration is contracted.