Section 100

Any interest imposed under section 85(2) or penalty imposed under this Act is not deemed to be part of the tax paid for the purposes of claiming relief under any of the provisions of this Act.

Any penalty imposed under section 13D(2), (4) or (6), 13O(3) or (5), 37(18B), 45(4), 87(1) or 91(4) is deemed to be interest on tax for the purposes of section 33(2) of the Limitation Act 1959.