Higher TDS rate for non-filers required where returns are not furnished and substantial tax was deducted. Section 206AB requires a deductor to deduct tax at a higher rate where a person has failed to furnish a return of income for the specified period and the tax deducted or collected during that period exceeds the specified limit; the provision operates alongside higher-deduction rules referenced with Section 206AA and specifies the deductor's obligation once the non-filing and threshold conditions are met.