Tax deduction certificates: electronic applications and system security enabled for lower or no tax deduction eligibility. Applications for certificates authorising deduction or collection of income-tax at lower rates or nil deduction must be made electronically under digital signature or electronic verification code; the systems heads are required to establish secure procedures, formats and archival and retrieval standards for data capture, transmission, document upload and issuance. Certificates are issued to the named person responsible for deducting or collecting tax or, where deductors exceed one hundred and are unidentified, to the applicant; Assessing Officers must determine existing and estimated tax liability by reference to estimated and prior years' incomes, existing liabilities, advance tax and amounts already deducted or collected.