Tax deduction at source from salaries: withholding rules, exemptions, and documentary proof requirements govern employer withholding practice. Employers must withhold tax at prescribed rates on salary income paid or payable from the commencement date, deducting tax only where estimated annual salary exceeds the threshold and allowing marginal relief where applicable. Perquisites valuation, repayments from compulsory deposit schemes, standard deduction for employment expenses (subject to ceilings and limitations for conveyance or employer provided vehicles), and specified deductions for insurance, provident fund and qualifying post office deposits must be taken into account. Exemptions for house rent allowance, education expenses for dependants, and foreign remuneration have specified eligibility conditions and documentary proof requirements; disbursing authorities must verify evidence before granting exemptions.