Composition levy option prescribes simplified fixed-rate payment, eligibility conditions, lapse on turnover breach, and no input tax credit. Composition levy allows a registered person below the prescribed turnover threshold to opt for a prescribed fixed-rate payment in lieu of regular tax, subject to eligibility conditions and exclusions; the option lapses on exceeding the turnover threshold, the optant may not collect tax nor claim input tax credit, and ineligible use of the scheme attracts tax determination and penalty under the assessment provisions.