Tax deduction at source under section 194C: deduction rates apply to contractor payments, increased by a Union surcharge. Payments to resident contractors by specified agencies require deduction of tax at source under section 194C on payment or credit, and contractors must deduct tax on payments to resident sub-contractors; no deduction is required where the contract consideration does not exceed the statutory threshold. An amendment mandates that such deductions be increased by a Union surcharge calculated on the tax deducted, applicable only to payments after the amendment's effective date, and the circular directs state disbursing officers and undertakings to comply and seek assistance from Income-tax Officers if needed.