Bill of supply requirements under GST: specified mandatory contents, electronic signature exceptions, and optional QR code mandate. Rule 49 mandates that a bill of supply for non-taxable supplies contain the supplier's name, address and GSTIN; a unique consecutive serial number for the financial year; date of issue; recipient's name, address and GSTIN or Unique Identity Number if registered; HSN code; description of goods or services; value of supply after discount or abatement; and the supplier's signature or digital signature. Provisions of rule 46 apply mutatis mutandis, electronic bills issued under the Information Technology Act need not bear a signature, and the Government may require a QR code by notification.