29Assessing procedure
(1)Except as otherwise provided, all assessments to tax shall be made by an inspector, and—
(a)if the inspector is satisfied that any return under the Taxes Acts affords correct and complete information concerning profits in respect of which tax is chargeable, he shall make an assessment accordingly,
(b)if it appears to the inspector that there are any profits in respect of which tax is chargeable and which have not been included in a return under Part II of this Act, or if the inspector is dissatisfied with any return under Part II of this Act, he may make an assessment to tax to the best of his judgment.
(2)All assessments to surtax shall be made by the Board and—
(a)if they are satisfied that a return under Part II of this Act of the income of an individual affords correct and complete information concerning the whole of his income computed in accordance with the provisions of the Income Tax Acts relating to surtax, they shall make an assessment accordingly, and
(b)if it appears to them that there has been a failure to make a return under Part II of this Act of the income of an individual, or if they are dissatisfied with such a return, they may make an assessment to surtax to the best of their judgment.
(3)If an inspector or the Board discover—
(a)that any profits which ought to have been assessed to tax have not been assessed, or
(b)that an assessment to tax is or has become insufficient, or
(c)that any relief which has been given is or has become excessive,
the inspector or, as the case may be, the Board may make an assessment in the amount, or the further amount, which ought in his or their opinion to be charged.
(4)All income tax at the standard rate which is charged for any year on any person under subsection (3)(c) above may, notwithstanding that it was chargeable under more than one Schedule, be included in one assessment and an appeal against an assessment under subsection (3)(c) above shall be to the Commissioners to whom an appeal would lie on a claim for the relief in connection with which the assessment is made.
(5)Notice of any assessment to tax shall be served on the person assessed and shall state the time within which any appeal against the assessment may be made.
(6)After the notice of assessment has been served on the person assessed, the assessment shall not be altered except in accordance with the express provisions of the Taxes Acts.
(7)Assessments to income tax at the standard rate which are under any provision in the Income Tax Acts to be made by the Board shall be made in accordance with this section, and as if in subsection (1)(a) and (b) above the references to the inspector were references to the Board.
(8)In this section " profits "—
(a)in relation to income tax, means income,
(b)in relation to capital gains tax, means chargeable gains,
(c)in relation to corporation tax, means profits as computed for the purposes of that tax,
and " return under Part II of this Act" includes a return under that Part as extended by section 39(3) of the principal Act (returns of income of husband and wife).