Composition scheme filing and payment procedure requires quarterly self-assessed payment and annual return to secure compliance. Registered persons under the composition scheme or availing the departmental notification must submit quarterly self-assessed tax statements in FORM GST CMP-08 by the eighteenth day of the month following each quarter and file the annual return in FORM GSTR-4 by the thirtieth day of April; timely submission of these forms for covered periods is treated as compliance with the Act's return and payment obligations.