Modes of verification under CGST Rules: Aadhaar and electronic verification codes authenticate submitted documents for compliance. Notification under sub rule (1) of rule 26 CGST Rules prescribes authorised electronic authentication methods: Aadhaar based Electronic Verification Code, electronic verification code generated via net banking login on the common portal, and electronic verification code generated on the common portal; where authentication is by these modes, verification must be completed within two days of furnishing documents.