TAN requirement: persons deducting or collecting tax at source must obtain TAN, limited exceptions permit PAN instead. Persons required to deduct or collect tax at source must obtain TAN, but specified withholding categories may use PAN in place of TAN. The PAN accommodation applies to withholding on certain immovable property transfers, certain rent payments by eligible individuals and HUFs, certain contractual/commission/brokerage/professional payments by eligible individual and HUF payers, and withholding on transfers of virtual digital assets; the exceptions are narrow and conditioned on the statutory eligibility criteria.