About James O'Brien
James O'Brien is a CPA (CPA Australia member) and registered tax agent with over 14 years of experience in Australian tax compliance and planning. Based in Melbourne, he advises individuals, investors, and small business owners on capital gains tax, PAYG withholding, income tax optimisation, and HECS-HELP debt management. James has worked extensively with ATO public rulings and Tax Determination documents, ensuring all advice aligns with current law. At CalcPhi, he is responsible for verifying all Australian tax calculator logic against ATO published rates, Tax Office legislation, and Federal Budget updates. His content is updated within 7 days of any ATO or Budget announcement affecting income tax, CGT, or withholding rates.
Articles by James O'Brien
Editorial Independence
All content produced by James O'Brien for CalcPhi is editorially independent. Calculator results and written content are never influenced by advertising relationships or affiliate commissions. All rates and regulatory figures are sourced directly from ATO, APRA, ASIC, RBA, or Services Australia publications. See our editorial standards for full details.