Section 31 - Tax invoice.

Tax invoice timing and documentation requirements under GST: obligations for goods, services, advances, reverse charge and continuous supplies.

Section 31 prescribes issuance and timing of a tax invoice: for goods, before or at removal or delivery; for services, before or within a prescribed period after provision. It authorises notifications specifying when alternate documents may suffice. Exceptions include revised invoices following registration, simplified treatment for low value supplies, requirement of a bill of supply for exempt or composition supplies, issuance of receipt vouchers for advance payments and refund vouchers where no supply occurs, and invoicing and payment voucher obligations under reverse charge. Continuous supply and approval sale arrangements have specific invoicing timings.