28‑100 Substantiation28‑100 Substantiation

#### 28‑100 Substantiation (1) To use this method, you must substantiate the \*car expenses under Subdivision 900‑C. (2) You must also keep a log book. Subdivision 28‑G explains:  how often you need to keep a log book;  how to keep a log book. The log book is relevant to estimating the number of business kilometres the \*car travelled in the period when you \*held it during the income year. (3) You must keep odometer records for the period when you \*held the \*car during the income year. Subdivision 28‑H tells you about odometer records, which document the total number of kilometres the car travelled in that period. (4) You must record the following information, in writing, before you lodge your \*income tax return: (a) your estimate of the number of \*business kilometres; and (b) the \*business use percentage. However, the Commissioner may allow you to record the information later. (5) You must retain the log book and the odometer records. Subdivision 28‑I has the rules about this.