Minor breach exemption limits penalties for trivial tax documentation errors while requiring hearing and proportional assessment. The Act prohibits penalising minor breach offences-trivial tax liabilities and documentation errors apparent on record-and requires penalties to be proportionate to the facts and severity of the breach. No penalty may be imposed without giving the person an opportunity of being heard, and orders must specify the breach and the applicable provision. Voluntary pre-discovery disclosure is a mitigating factor; the section excludes penalties already prescribed as fixed sums or fixed percentages.