Tax collection from non-filers requires elevated source collection rates on payments where return-filing and withholding thresholds are unmet. A special collection-at-source rule requires higher tax collection on payments to persons who failed to file returns for the two relevant prior assessment years and whose aggregate TDS and TCS in each year meets the statutory threshold; collection is at the higher of twice the applicable rate under Chapter XVII-BB or a fixed minimum rate, and, if other non-filer higher-collection rules apply, the highest applicable rate governs. The 'specified person' excludes non-residents without a permanent establishment, which includes a fixed place of business.