One clarification for Australian readers. The standard-versus-itemised choice belongs to the US system. An ordinary Australian return doesn't work this way, and the ATO's new work-related standard deduction is a separate concept. This guide is for Australians with US filing obligations: US citizens and residents living here, cross-border households, and business owners.
Figures below come from the IRS's 2027 adjustments. Confirm them against final IRS guidance before you file.
Key Takeaways
- The standard deduction is fixed by filing status; itemizing means totalling eligible expenses on Schedule A.
- Itemize only when your allowable total beats your standard deduction.
- Mortgage interest, state and local taxes, charity and medical costs can tip the balance, subject to limits.
- Keep US and Australian calculations separate, and get cross-border advice where they overlap.
Standard Deduction vs. Itemized Deductions: Quick Comparison
| Standard deduction | Itemized deductions | |
|---|---|---|
| What it is | Fixed IRS amount for your filing status | Eligible expenses listed on Schedule A |
| 2027 amount | $16,600 single; $33,200 joint | No fixed figure; depends on expenses and limits |
| Best suited to | Simple returns, few deductible expenses | Heavy mortgage interest, taxes, charity or medical costs |
| Records | Minimal | Receipts, statements, acknowledgements |
| Decision rule | Take it when it's larger | Take it only when the allowable total exceeds it |
Understanding the Standard Deduction and Itemized Deductions
What Is the Standard Deduction?
The standard deduction reduces your taxable income by a fixed amount. It does not cut your tax bill dollar for dollar. A $16,600 deduction at a 24% marginal rate saves roughly $3,984 in tax, not $16,600.
The IRS published 2027 amounts in Rev. Proc. 2026-35:
| Filing status | 2026 | 2027 |
|---|---|---|
| Single | $16,100 | $16,600 |
| Married filing jointly | $32,200 | $33,200 |
| Married filing separately | $16,100 | $16,600 |
| Head of household | $24,150 | $24,925 |
| Qualifying surviving spouse | $32,200 | $33,200 |
Age 65 or older, or blindness, adds $1,700 for 2027 ($2,100 if unmarried and not a surviving spouse). Dependents get the greater of $1,400 or earned income plus $500, capped at the basic amount.
What Are Itemized Deductions?
You list eligible expenses on Schedule A and carry the allowed total to Form 1040. The main categories:
- Medical and dental costs above 7.5% of AGI
- State and local taxes (SALT), under a cap
- Home mortgage interest
- Charitable gifts, above 0.5% of AGI from 2026
- Investment interest, limited to net investment income
- Personal casualty losses from federally declared (or qualifying state-declared) disasters
Key Limits to Know
- Mortgage interest: generally acquisition debt up to $750,000 ($375,000 if married filing separately). Older pre-December 2017 debt can keep the $1 million limit.
- SALT: the 2026 cap is $40,400, phasing down above $505,000 of MAGI to a $10,000 floor. For 2027 the statute sets 101% of the prior year's figures. Confirm the published figure before you rely on it.
- High earners: from 2026, itemized deductions are reduced by 2/37 of the amount by which income reaches the 37% bracket.
- Charity: a separate non-itemizer deduction of up to $1,000 ($2,000 joint) exists from 2026. It's not on Schedule A.
Business expenses, above-the-line adjustments and credits are not itemized deductions. Sole-trader costs go on Schedule C. Adjustments reduce AGI before the deduction choice. Credits cut tax directly.
Special Situations: Married and Cross-Border Filers
If you're married filing separately and your spouse itemizes, your standard deduction drops to zero. Coordinate before either of you files.
For Australians with US obligations, several issues sit outside the deduction choice:
- US citizens and residents are taxed on worldwide income, wherever they live.
- Income excluded under the foreign earned income exclusion still counts toward filing requirements.
- You choose each year between the foreign tax credit and deducting foreign income taxes.
- The US-Australia treaty's saving clause generally preserves US taxation of citizens.
- Report in USD, generally at the spot rate when income is received or expenses are paid.
- Australian deductions, including superannuation contributions, don't automatically qualify on Schedule A.
Direct gifts to Australian charities generally don't qualify either. Personal foreign property taxes are also excluded from the SALT category.
How to Decide Which Deduction to Take in 2027
- Confirm your filing status and note the 2027 standard deduction, plus any age or blindness additions.
- Gather records: mortgage statements, tax bills, charity acknowledgments, medical receipts, investment-interest records.
- Apply each limit first. Gross expenses are not the same as deductible amounts. Medical costs count only above 7.5% of AGI, for example.
- Compare the totals. The larger allowable figure wins, and it reduces taxable income rather than producing a refund.
- Weigh the admin burden. Itemizing demands support for every line.
Records matter. The IRS generally expects you to keep them for three years after filing, or six if you omitted more than 25% of gross income. Charitable gifts of $250 or more need a written acknowledgment, obtained by the earlier of filing or the due date including extensions.
Some situations warrant a professional review:
- US taxpayers living in Australia
- Dual-status or dual-filing households
- Separate returns
- Large charitable gifts
- Foreign business interests
- Uncertain residency
If that sounds like you, VJM Global's cross-border tax team can help you assess whether its US individual return preparation fits your circumstances.
Practical 2027 Scenarios and Filing Checklist
Both scenarios are hypothetical: a single filer, age 40, AGI of $100,000, no foreign income exclusion and no dependents.
Scenario 1: Limited Expenses
This filer rents and gives $1,000 to charity. After the 0.5% AGI floor ($500), only $500 is deductible. Itemized total: $500. Standard deduction: $16,600. The standard deduction wins by $16,100.
Scenario 2: Expense-Heavy
| Item | Gross | Allowed |
|---|---|---|
| Medical | $15,000 | $7,500 (above 7.5% of $100,000) |
| SALT | $8,000 | $8,000 |
| Mortgage interest | $18,000 | $18,000 |
| Charity | $10,000 | $9,500 (above $500 floor) |
| Total | $43,000 |
Itemizing beats the $16,600 standard deduction by $26,400 of taxable income. At a 24% marginal rate, that's roughly $6,336 in extra tax savings.
Pre-Filing Checklist
- Confirm filing status
- Verify the official 2027 IRS amounts
- Total only eligible expenses
- Keep supporting documents
- Check married-filing-separately coordination
- Separate US calculations from Australian ones
For context, in tax year 2022 the IRS reported 88.6% standard and 9.5% itemized returns. That's history, not a 2027 forecast.
Conclusion
Neither option is automatically better. Work out your allowable 2027 itemized total and compare it with the standard deduction for your filing status.
The standard deduction offers simplicity; itemizing pays off in expense-heavy years. For Australian readers, this choice applies only to your US return and doesn't replace Australian tax advice.
Frequently Asked Questions
How does the standard deduction affect your taxes?
It lowers taxable income by a fixed amount. Your actual saving depends on your marginal rate, filing status and other return details.
What is the standard deduction for each year?
Amounts change by tax year and filing status. The 2027 figures are in the IRS announcement. A 2027 return is filed in 2028, normally by 15 June for qualifying filers abroad.
Is it worth taking the standard deduction?
Yes, when your allowable itemized total is lower, records are thin or simplicity matters. Compare both methods under 2027 rules.
How do I itemize taxes?
Gather eligible expenses, apply each limit, keep records, complete Schedule A and carry the allowed total to Form 1040.
What is one disadvantage of itemizing?
Recordkeeping. You must document every claimed expense, and you gain nothing if the total doesn't exceed the standard deduction.
