7A. Power to make correction:
(1) If it is learnt from an application made by a tax- payer or from any other source that tax has been so assessed that the figure of tax  is lower or higher because of some error in any statements or mathematical error in valuating the house and land pursuant to this Act, the Tax Officer may, within Two years from the date of assessment of tax, correct the error and reassess the tax.
(2) If the amount of tax to be set after making correction the error in the tax assessment order pursuant to Sub-section (1) becomes less than that of tax
assessed previously, prior to issuing such tax assessment order, approval of the Director General of the Department of Tax shall be obtained by executing a memo
(Parcha) setting out clear reasons therefor.
(3) If the amount of tax to be set after making correction pursuant to Sub- section (1) becomes higher than that of tax assessed previously, prior to correcting
the error in the tax assessment order, a memo setting out clear reasons therefor has to be executed, the tax-payer has to be given a written notice about it and given a
reasonable opportunity to defend him/herself in respect of the tax payable by him/her