(1) You have a decreasing adjustment if:
(a) you made a * taxable supply; and
(b) the whole or part of the * consideration for the supply has not been received; and
(c) you write off as bad the whole or a part of the debt, or the whole or a part of the debt has been * overdue for 12 months or more.
The amount of the decreasing adjustment is 1 / 11 of the amount written off, or 1 / 11 of the amount that has been overdue for 12 months or more, as the case requires.
(2) However, you cannot have an * adjustment under this section if you * account on a cash basis.