Deduction or collection at source treated as payment on behalf of the taxpayer, and advance payment remains required. The provision prescribes modes for discharge of income-tax liabilities by way of deduction or collection at source, advance payment, or payment under the specified provision, with such payments governed by the Chapter's rules irrespective of later assessment. Tax sums deducted, collected or paid to the Central Government are treated as payment of tax on behalf of the person from or in respect of whose income the tax was deducted or collected or from whom it was collected, and the Board may make rules for crediting such tax and determining the tax year for credit.