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James O'Brien, Chartered Tax Adviser & CPA at CalcPhi
CPA

James O'Brien

Chartered Tax Adviser & CPA

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.

Approach to Financial Guidance

James O'Brien approaches every article by asking: what does a financially literate reader actually need to make this decision with confidence? That means going beyond regulatory definitions to explain practical implications — who benefits, who doesn't, and what the numbers look like across typical income and wealth levels.

All figures are cross-checked against the ATO's individual tax rates schedule, APRA's quarterly statistics, and ASIC's MoneySmart guidance before publication. Super balance projections account for the contributions tax, the earnings tax inside accumulation phase, and the correct concessional cap for each financial year — not simplified approximations.

Mortgage and property content uses actual reducing-balance amortisation, correctly accounts for the APRA serviceability buffer in borrowing capacity estimates, and models offset account savings using the daily interest calculation method used by Australian lenders.

All CalcPhi articles authored by James O'Brien are reviewed by a second qualified team member before publication. Regulatory figures are updated within 48 hours of any relevant notification or rate change.

Data sources: Tax rates and thresholds sourced from the Australian Taxation Office (ATO) and ASIC MoneySmart. Updated for FY 2025-26. For personalised advice, consult a licensed financial adviser (AFS licence).