Tax deduction at source from salaries: employers must compute withholding on estimated taxable salary including perquisites and apply prescribed exemptions. Employers must deduct income-tax at source from salary by computing tax on the employee's estimated annual salary inclusive of monetary pay and prescribed valuation of perquisites, applying exemptions and deductions (including gratuity, leave encashment, retrenchment and approved voluntary retirement payments, house rent allowance, standard deduction and permitted savings deductions) to arrive at taxable income. New procedural provisions allow aggregation of salary from multiple employers, relief for arrears or advances, require allotment and quoting of a tax-deduction account number, and impose interest, rounding rules and penalties for non-compliance; specific valuation rules and evidentiary requirements for allowances and perquisites are prescribed.