PAN requirement for TDS: failure to furnish PAN triggers higher withholding rate under income-tax withholding rules. Section 206AA mandates that persons entitled to receive income subject to tax deduction at source must furnish their PAN to the deductor; if PAN is not furnished, the deductor must deduct tax at a higher rate, making PAN disclosure the operative compliance requirement and non-furnishing the trigger for elevated withholding.