PIT audit yield relative to PIT collections

Notes:

Each panel shows the median audit-yield ratio for respondent jurisdictions in the GNI group, per year. The ratio for each jurisdiction-year is the value of additional PIT assessments raised from audits and verification actions (ISORA A.83, including penalties and interest) divided by PIT net revenue collected in that year (ISORA A.6). Both are reported in thousands of local currency, so the ratio is unit-free and comparable across jurisdictions.

Interpretation: a ratio of 2% means audits added uplift equivalent to roughly 2% of baseline PIT collection. Higher values can reflect either stronger audit selection and yield or a larger compliance gap being closed — the ratio alone does not distinguish those two causes. Values are small, so they are displayed to two decimal places.

Jurisdictions are included in each year’s median only when both figures are reported and PIT revenue is positive. ISORA does not collect a PIT-specific count of audits or audits finding a tax adjustment, so a classic ‘audit hit rate’ cannot be built at the PIT level from this survey.

When a jurisdiction is highlighted, its own ratio series is overlaid as a dashed red line on its GNI panel. The ratio has no natural ceiling, so the four panels share a y-axis scaled to the tier medians; a highlighted jurisdiction above that ceiling is clipped for readability.

Source: ISORA Derived Tables A.6, A.83 (PIT net revenue; additional assessments from audits).