Electronic authentication for GST filings: digital signature, e signature or electronic verification code with authorised signatories. Rule 26 requires electronic submission and authentication of all GST applications, returns and documents using a digital signature certificate, e signature under the Information Technology Act, 2000, or other Board notified verification modes; each online document must be signed or verified through an electronic verification code where applicable with entity specific authorised signatories; notices, certificates and orders are to be issued electronically by authorised officers using digital signature, e signature or other notified verification modes.