The 30-day rule does not extend the e-invoicing deadline, it removes it.
Taxpayers with aggregate annual turnover of Rs 10 crore or more in any financial year from 2017-18 onward cannot report an e-invoice to the IRP more than 30 days after the invoice
The 30-day count runs from the invoice date, not from the date you attempt to submit it, so a backdated or delayed invoice can already be outside the window before you even try to
There is no late-reporting fallback on the IRP for this rule.
Below Rs 10 crore turnover the 30-day restriction does not currently apply, but the e-invoicing mandate itself starts at Rs 5 crore, so many sellers are already reporting IRNs
No. It applies specifically to taxpayers with aggregate annual turnover of Rs 10 crore or more, in any financial year since GST began.
The full guide has the formats, the deadlines and the worked examples.