Composition-scheme return obligations: quarterly GSTR-4 filing, inward/outward reconciliation and tax liability reporting. GSTR-4 prescribes the quarterly return for composition-scheme taxpayers requiring consolidated, rate-wise disclosure of inward supplies (segregated by registered supplier, reverse charge, unregistered supplier and import of services), outward supplies, and reconciliation with FORM GST CMP-08. The form auto-populates key identifiers and turnover, records tax, interest, late fee, TDS/TCS credits and refunds from the electronic cash ledger, accommodates advances and amendments to earlier-period details, and requires verification by an authorised signatory.