As per Lawkidunya
(1) 4[Subject to the provisions of 5[section 8 and] , for] the purpose of determining his tax liability in respect of taxable supplies made during a tax period, a registered person shall 6[, subject to the provisions of section 73,] be entitled to deduct input tax 7[paid 8[or payable 9[during the tax period for the purpose of taxable supplies made, or to be made, by him] from the output tax 10[excluding the amount of further tax under sub-section (1A) of section 3.] 11[ ] that is due from him in respect of that tax period and to make such other adjustments as are specified in Section 9 12.
13 Provided that where a registered person did not deduct input tax within the relevant period, he may claim such tax in the return for any of the six succeeding tax periods. A registered person shall not be entitled to deduct input tax from output tax unless,- (i) in case of a claim for input tax in respect of a taxable supply made 14[***], he holds a tax invoice 15[in his name and bearing his registration number] in respect of such supply for which a return is furnished 1[:] Provided that from the date to be notified by the Board in this respect, in addition to above, if the supplier has not declared such supply in his return or he has not paid amount of tax due as indicated in his return; (ii) 2 in case of goods imported into Pakistan, he holds bill of entry or goods declaration in his name and showing his sales tax registration number, duly cleared by the customs under section 79 3[, section 81] or section 104 of the Customs Act, 1969 (IV of 1969); 4[in case of goods purchased in auction, he holds a treasury challan, 5[in his name and bearing his registration number,] showing payment of sales tax;] 6[(iv) ***]
(3) Notwithstanding anything in sub-sections (1) and (2), the 8[Board with the approval of the Federal Minister-in-charge] may, by a special order, subject to such conditions, limitations or restrictions as may be specified therein allow a registered person to deduct input tax paid by him from the output tax determined or to be determined as due from him under this Act.]
9[(4) Notwithstanding anything contained in this Act or rules made there under, the 6[Board with the approval of the Federal Minister-in-charge] may, by notification in the official Gazette, subject to such conditions, limitations or restrictions as may be specified therein, allow a registered person or class of persons to deduct such amount of input tax from the output tax as may be specified in the said notification.]