Under the GST framework, late filing attracts interest at eighteen percent per annum on the unpaid tax liability, plus a late fee of fifty rupees per day per return. That clock starts running from the due date, not from the date you realise the return is overdue. For a business filing monthly across multiple GSTINs, a single missed cycle can compound into a significant penalty before anyone notices.
Beyond the financial hit, non-compliance blocks your ability to claim Input Tax Credit. Suppliers who fail to file GSTR-1 on time cause their buyers to lose ITC entitlement in GSTR-2B, a knock-on effect that can disrupt your working capital and strain vendor relationships. The GST department has also increased scrutiny notices under ASMT-10, DRC-01 and scrutiny of returns, and responding to these requires a detailed audit trail of every invoice, every credit and every reconciliation entry. Staying clean is far cheaper than catching up.