4. Entry into effect

The amendments mentioned in paragraph 3 have effect —

with respect to taxes withheld at source, in respect of amounts paid, deemed paid or liable to be paid (whichever is the earliest), on or after 1 January 2020; and (b)with respect to taxes other than those withheld at source, where the income is derived or received in a basis period beginning on or after 1 October 2019.