Enforcement intensity

Audit hit rates and additional assessments raised, drawn from the International Survey on Revenue Administration (ISORA) — a self-reported dataset, not an independent audit of the audits.

Audit hit rate

Hit rate is self-reported by each administration to ISORA, not an independently measured figure — definitions of what counts as an audit, and the tax years covered, vary between administrations. The year shown is the most recent one that administration has reported. Read a high or low number as a statement about how that authority describes its own audit programme, not as a ranking of how aggressive it actually is.

Additional assessments raised, % of tax collections

This is additional tax assessed through all audits and verification actions, as a share of tax collections — again self-reported by each administration to ISORA rather than independently measured. Reporting years and definitions of what counts as a verification action differ between administrations, so the figure shown is the most recent year that authority reported, and comparisons across countries should be read as comparisons of self-description, not of enforcement outcomes.