Tax Deduction at Source requirement: deposit, certificate issuance, TAN registration and quarterly return obligations enforced. Persons deducting tax under Section 36A must deposit deducted tax via Form DVAT-20 within the prescribed time and pay interest for delay, issue a quadruplicate Tax Deduction Certificate in Form DVAT-43 with specified timelines for furnishing copies and retaining records, apply for a TAN in Form DVAT-44 within seven days of deduction to receive Form DVAT-45, file quarterly returns in Form DVAT-48 within twenty-eight days of quarter end, and submit amendment or cancellation applications electronically in Form DVAT-45A.