(1) Notwithstanding subsection (2), where an electronic return or a paper return is delivered in relation to an instrument required to be stamped by means of the e-stamping system, there shall be included on that return an assessment of such amount of stamp duty that, to the best of the accountable person's knowledge, information and belief, ought to be charged, levied and paid on the instrument and the accountable person shall pay, or cause to be paid, the stamp duty so assessed together with interest calculated in accordance with section 159D unless the Commissioners make another assessment to be substituted for such assessment.