(a) you have a * decreasing adjustment relating to a supply made by you through an agent or made to you through an agent; and
(b) neither you nor your agent holds an * adjustment note or * third party adjustment note for the adjustment when you give to the Commissioner a * GST return for the tax period to which the adjustment would otherwise be attributable;
(c) the adjustment (including any part of the adjustment) is not attributable to that tax period; and
(d) the adjustment (or the part of the adjustment) is attributable to the first tax period for which you give to the Commissioner a GST return at a time when you or your agent holds that adjustment note or third party adjustment note.
(2) This section has effect despite subsections 29-20(3) (which is about the requirement to hold an adjustment note) and 134-15(1) (which is about the requirement to hold a third party adjustment note).