According to the Finance Min. a Tax Identification Number (TIN) doesn't automatically make someone liable for income tax.
The obligation arises only when income exceeds the annual tax exemption limit of Rs. 1.2 mil for those above 18.
However, submitting the TIN is mandatory when opening a current account, requesting building plan approval, registering a motor vehicle, renewing a license & registering title to land from 01 Feb. PMD