A person may not claim a deduction under this section in respect of a bad debt relating to a supply unless the deduction is claimed in a return under this Division filed within four years after the day on or before which a return of the person was required to be filed for the reporting period in which the supplier has written off the bad debt in its books of account.
A person may not claim a deduction under subsection (1) in respect of an amount that the person has, during a particular reporting period of the person, written off in its books of account as a bad debt unless the deduction is claimed in a return under this Division filed by the person within four years after the day on or before which the return under this Division for the particular reporting period is required to be filed.