(1) If any person—
(a) has not furnished returns required under this Regulation by the prescribed date; or
(b) has furnished incomplete or incorrect returns; or
(c) has furnished a return which does not comply with the requirements of this Regulation; or
(d) for any other reason the Commissioner is not satisfied with the return furnished by a person, the Commissioner may for reasons to be recorded in writing assess or reassess to the best of his judgment the amount of net tax due for a tax period or more than one tax period by a single order so long as all such tax periods are comprised in one year.
(2) If, upon the information which has come into his possession, the Commissioner is satisfied that any person who has been liable to pay tax under this Regulation in respect of any period or periods, has failed to get himself registered, the Commissioner may for reasons to be recorded in writing, assess to the best of his judgment the amount of net tax due for such tax period or tax periods and all subsequent tax periods.
(3) Where the Commissioner has made an assessment under this section, the Commissioner shall forthwith serve on that person a notice of assessment of the amount of any additional tax due for that tax period.
(4) Where the Commissioner has made an assessment under this section and further tax is assessed as owed, the amount of further tax assessed is due and payable on the same date as the date on which the net tax for the tax period was due.