Any returns under the Taxes Acts shall be in such form as the Board prescribe, and in prescribing income tax forms under this subsection the Board shall have regard to the desirability of securing, so far as may be possible, that no person shall be required to make more than one return annually of the sources of his income and the amounts derived therefrom.

Any notice or direction requiring any return to be made under the Taxes Acts to an inspector or other officer of the Board may be issued or given in the name of that officer, or as the case may be in the name of the Board, by any officer of the Board, and so as to require the return to be made to the first-mentioned officer.

Where the Board or an inspector or other officer of the Board have in accordance with section 29 of this Act, or any other provision of the Taxes Acts, decided to make an assessment to tax, and have taken all other decisions needed for arriving at the amount of the assessment, they may entrust to some other officer of the Board responsibility for completing the assessing procedure, whether by means involving the use of a computer or otherwise, including responsibility for serving notice of the assessment on the person liable for tax.

Where an officer of the Board has decided that an amount of tax carries interest under section 88 of this Act and has taken the decisions needed for arriving at the date when for the purposes of that section that tax ought to have been paid, he may entrust to any other officer of the Board responsibility for completing the determination procedure, whether by means involving the use of a computer of otherwise, including responsibility for serving notice of the determination on the person liable to the interest.

Where an officer of the Board has decided to impose a penalty under section 100 of this Act and has taken all other decisions needed for arriving at the amount of the penalty, he may entrust to any other officer of the Board responsibility for completing the determination procedure, whether by means involving the use of a computer or otherwise, including responsibility for serving notice of the determination on the person liable to the penalty.

Any return or assessment or other document relating to chargeable gains or tax on capital gains may be combined with one relating to income or income tax.

Every assessment, F4determination of a penalty, duplicate, warrant, notice of assessment F4, of determination or of demand, or other document required to be used in assessing, charging, collecting and levying tax F4or determining a penalty shall be in accordance with the forms prescribed from time to time in that behalf by the Board, and a document in the form prescribed and supplied or approved by them shall be valid and effectual .