Collection of tax at source now applies to purchase price including excise and issue price, widening TCS base. Collection of income-tax at source applies to profits and gains from trading in specified goods, with purchase price construed to include any amount paid or payable by the buyer (excluding auction bid amounts) so that excise duty and analogous charges, including the issue price or 'Nirgam Mulya', form part of the purchase price. Persons defined as sellers, including governments, local authorities, corporations and co-operative societies, must collect tax at source at prescribed rates based on this inclusive purchase price. The amendments apply from the assessment year 1991-92 and cover collections made during the financial year 1990-91.