Tax Deduction at Source on Contractor Payments requires payers to withhold tax and meet payment, certificate and reporting obligations. Section 194C mandates withholding tax on payments to resident contractors by specified payers and on payments by contractors to resident sub-contractors, subject to surcharge and a small-sum exemption; Assessing Officers may grant Form No.13C certificates for lower or nil deduction. Deductors must deposit withheld tax within prescribed timeframes, furnish Form No.16B certificates, quote TAN on documentation, and file an annual return in Form No.26C. Failures attract interest, penalties, and potential prosecution under relevant provisions.