is there gst on bad debt
1 The GST adjustment is to take place in the period when the bad debt is written off or when the owner becomes aware that the debt is bad. 2  For the debt to be considered bad, it needs to be overdue for 12 months.n order to do so, the ruling states that: GST must have been attributed. A decreasing adjustment for a bad debt can arise in respect of a supply if either 1  : you attributed the GST on the supply on your BAS in a previous tax period, or.