Time of supply under reverse charge: earliest of receipt, payment entry, or expiry of the invoice statutory period. Time of supply for goods under the reverse charge mechanism is the earliest of: date of receipt of goods; date of payment recorded or debited in the recipient's accounts; or the date immediately following thirty days from issue of the supplier's invoice or document; if none are determinable, the entry date in the recipient's books. Invoice issuance timing and special rules on advances, notified reverse-charge categories, and promoter-specific shortfall computations affect application.