We seek feedback and advice about how we estimate the gap from our external and internal subject matter experts. Based on the advice and assessment, the reliability rating for this estimate is medium with a score of 17, which is unchanged from the score published in 2024.
We have stratified the sampling process to ensure it is representative of the wider population.
We engage former Deputy President of the Administrative Appeals Tribunal, Mr Stephen Frost, for further assurance. He verifies the accuracy and quality of a sample of the audit results that underpin our tax gap estimate.
Figure 6: Reliability rating scale from very low to very high – small business income tax gap