Electronic invoicing requirement: invoice validity conditioned on FORM GST INV-01 upload and Invoice Reference Number issuance. The amendment requires notified classes of registered persons to prepare invoices by including particulars in FORM GST INV-01 and obtaining an Invoice Reference Number by uploading that information on the Common Goods and Services Tax Electronic Portal, subject to manner, conditions and restrictions specified by notification; invoices issued otherwise will not be treated as invoices and certain earlier invoice provisions shall not apply to invoices prepared in this manner.