—(1) Where a person has failed to make any returns required under this Act or to keep any documents and afford the facilities necessary to verify such returns or where it appears to the Comptroller that such returns are incomplete or incorrect, the Comptroller may to the best of his judgment assess the amount of tax due from that person and notify him of it.
(2) In any case where —
an amount has been repaid to any person as being a repayment of tax, which ought not to have been repaid; or
an amount has been paid to any person as being due to him in accordance with section 19(5), which ought not to have been paid to him,
the Comptroller may assess that amount as being tax due from him for the prescribed accounting period in which the amount was repaid or, as the case may be, paid and accordingly notify him of the assessment.
(3) Where a person is assessed under subsections (1) and (2) in respect of the same prescribed accounting period, the assessments may be combined and notified to him as one assessment.
(4) Where the person failing to make a return, or making a return which appears to the Comptroller to be incomplete or incorrect, was required to make the return as a personal representative, trustee in bankruptcy, receiver, liquidator or person otherwise acting in a representative capacity in relation to another person, subsection (1) shall apply as if the reference to tax due from him included a reference to a tax due from that other person.
(5) An assessment under subsection (1) or (2) of an amount of tax due for any prescribed accounting period shall not be made —
in the case of a prescribed accounting period ending before 1st January 2007, more than 7 years from the end of the prescribed accounting period; and
in the case of a prescribed accounting period ending on or after 1st January 2007, more than 5 years from the end of the prescribed accounting period.
(5A) Notwithstanding subsection (5), where, in the opinion of the Comptroller, any form of fraud or wilful default has been committed by or on behalf of any person in connection with or in relation to tax, the Comptroller may for the purpose of making good any loss of tax or payment or refund of tax attributable to fraud or wilful default, make an assessment at any time.
(6) Where a taxable person has acquired or imported any goods in the course or furtherance of any business carried on by him, the Comptroller may require him from time to time to account for the goods.
(6A) If the taxable person fails to prove that —
the goods have been or are available to be supplied by him or have been exported from Singapore otherwise than by way of supply; or
the goods have been lost or destroyed,
the Comptroller may assess to the best of his judgment and notify the taxable person of the amount of tax that would have been chargeable in respect of the supply of the goods if they had been supplied by him.
(7) In any case where —
as a result of a person’s failure to make a return for a prescribed accounting period, the Comptroller has made an assessment under subsection (1) for that period;
the tax assessed has been paid but no proper return has been made for the period to which the assessment related; and
as a result of a failure to make a return for a later prescribed accounting period, being a failure by the person referred to in paragraph (a) or a person acting in a representative capacity in relation to him, as mentioned in subsection (4), the Comptroller finds it necessary to make another assessment under subsection (1),
(8) Where it appears to the Comptroller that the amount which ought to have been assessed in an assessment under this section exceeds the amount which was so assessed, the Comptroller may —
under the same provision as that assessment was made; and
within the period during which that assessment could have been made,
make a supplementary assessment of the amount of the excess and shall notify the person accordingly.
(9) Where an amount has been assessed and notified to any person under subsection (1), (2), (6A) or (8), it shall, subject to the provisions of this Act as to review and appeals, be deemed to be an amount of tax due from him and may be recovered accordingly, unless, or except to the extent that, the assessment has subsequently been withdrawn or reduced.
(10) The Comptroller may at any time make all such alterations in or additions to an assessment made under this section as he thinks necessary to ensure the correctness thereof and notify the person accordingly.
(10A) Where the Comptroller raises an assessment under subsection (1) upon the failure of a person to make any returns, and, subsequent to such assessment, the person makes a return, the Comptroller may, in his discretion, take into account the return and revise his assessment as he deems fit.
(10B) For the purpose of subsection (10A), where a person makes a return in respect of a prescribed accounting period ending on or after 1st January 2007 more than 5 years from the end of the prescribed accounting period, the return shall be treated as not having been made.
(11) For the purposes of this section, notification to a personal representative, trustee in bankruptcy, receiver, liquidator or person otherwise acting as aforesaid shall be treated as notification to the person in relation to whom he so acts.
[UK VAT Act 1983, Sch. 7 Para. 4; UK FA 1985, s. 22 (7)]