Introduction
There is no single income figure that decides whether you must file Form 1040. The answer depends on gross income, filing status, age, dependency status, income type and a handful of special triggers.
Form 1040 is a US federal individual income tax return. If you live in Australia, a US filing requirement is separate from your Australian tax return. One does not replace the other.
This guide uses the 2025 tax year figures from IRS Publication 501 and the Form 1040 instructions. It covers the ordinary thresholds, the exceptions, and why you might file even when you don't have to. All amounts are in US dollars unless marked A$.
Key Takeaways
- Thresholds change with filing status, age and whether someone can claim you as a dependent.
- Gross income and tax owed are different tests, so you may have to file and still owe nothing.
- Self-employment, retirement distributions and certain extra taxes can trigger filing below the threshold.
- Living in Australia doesn't end US obligations for citizens or green-card holders.
What Form 1040 Is and Who Usually Uses It
What does Form 1040 report?
Form 1040 reports your income, deductions, credits, dependants, withholding, and final federal tax position. Supporting documents vary. Common ones are the W-2 (employer wages), 1099 series (other payments), 1099-R (pension and retirement distributions) and 1042-S (a foreign person's US-source income). Most taxpayers need only a few of these.
Which version of the form may apply?
| Form | Use |
|---|---|
| 1040 | Standard annual individual return |
| 1040-SR | Same return with larger text, for those 65+ |
| 1040-NR | Nonresident aliens |
| 1040-X | Amending a filed return |
| 1040-ES | Estimated tax payments only |
Form 1040-ES doesn't replace the annual return. It only helps you pay during the year.
Filing requirement versus tax liability
Having to file is separate from owing tax. Withholding, estimated payments, deductions, credits and foreign tax relief may bring your balance to zero. A nonresident engaged in a US trade or business may need to file even with no income, or even when a treaty exempts the income.
How Income Thresholds Determine Whether You Must File
The main threshold factors
Under Publication 501, you file when gross income is at least the amount below. These are the 2025 figures for taxpayers who can't be claimed as someone's dependant.
| Filing status | Under 65 | Age 65+ |
|---|---|---|
| Single | $15,750 | $17,750 |
| Married filing jointly | $31,500 (both under 65) | $33,100 (one 65+); $34,700 (both) |
| Married filing separately | $5 | $5 |
| Head of household | $23,625 | $25,625 |
| Qualifying surviving spouse | $31,500 | $33,100 |
Age is measured at the end of the tax year. Filing status isn't a free choice. Marital status, household circumstances and qualifying dependants decide which one applies.
The married-filing-separately figure is just $5, so almost anyone in that status must file.
What counts as gross income?
Gross income is money, goods, property and services that aren't exempt from tax. That includes:
- Wages and business income
- Interest and dividends
- Capital gains and rental income
- Unemployment compensation
- Taxable retirement distributions
- Foreign income, even if you later exclude it on Form 2555
Tax-exempt income is generally left out, though tax-exempt interest feeds into the Social Security calculation. Don't treat "income below the standard deduction" as a universal rule. The filing table is its own test.
Separate rules for dependants
If someone can claim you as a dependant, Table 2 of Publication 501 applies. It has three alternative triggers, and you file if any is met. For a single dependant under 65 and not blind in 2025:
- Unearned income over $1,350
- Earned income over $15,750
- Gross income over the larger of $1,350 or earned income (capped at $15,300) plus $450
Take a student earning $4,000 from a part-time job who also receives $1,500 in dividends. Wages alone are well under the earned-income trigger. But $1,500 of unearned income exceeds $1,350, so a return is required.
Situations That Can Require a Return Below the Normal Threshold
Self-employment and gig income
Net self-employment earnings of $400 or more require a return, even when total income is far below the usual threshold. This rule applies to freelancers, contractors and creators.
The test uses net earnings after business expenses, not gross receipts. For the ordinary gross-income test, service businesses generally count gross receipts, and merchandise businesses subtract cost of goods sold.
Additional taxes and special income
Other 2025 triggers include:
- Alternative minimum tax
- Additional tax on early retirement distributions
- Household employment taxes
- Social Security or Medicare taxes not withheld, such as on tips
- HSA, Archer MSA or Medicare Advantage MSA distributions
- Advance premium tax credit payments, reconciled on Form 8962
- Church employee wages of $108.28 or more
Excess IRA contributions can require Form 5329. If no return is otherwise required, Form 5329 can be filed by itself.
Social Security benefits
Social Security benefits alone don't require filing. Benefits may become partly taxable when combined with other income. The IRS starts with half your benefits plus other income, including tax-exempt interest. Per Publication 915, the base amounts are:
- $25,000 for single, head of household and qualifying surviving spouse
- $32,000 for married filing jointly
- $0 for married filing separately if you lived with your spouse at any time in 2025
Up to 85% of benefits can be taxable. That doesn't mean they're taxed at 85%. Look at all income sources together.
Foreign financial reporting
FBAR and Form 8938 are separate from Form 1040. Having one obligation doesn't mean you have the other.
| Report | Threshold |
|---|---|
| FBAR | Aggregate foreign accounts over $10,000 at any time |
| 8938, US-based, unmarried | Over $50,000 at year end or $75,000 any time |
| 8938, US-based, joint | Over $100,000 or $150,000 |
| 8938, abroad, unmarried | Over $200,000 or $300,000 |
| 8938, abroad, joint | Over $400,000 or $600,000 |
FBAR goes to FinCEN, not with your return, due 15 April and automatically extended to 15 October. Form 8938 attaches to your return. If no return is required, no 8938 is required, but a separate FBAR duty can remain.
Don't assume how Australian accounts, superannuation or pensions are classified. Have a tax professional review the classification.
State and local obligations
A federal decision doesn't settle state or local filing. If you lived, worked or earned income in a US state, check that state's rules separately.
Do You Need to File a US Return While Living in Australia?
US citizens and green-card holders abroad
US citizens and lawful permanent residents (green-card holders) are taxed on worldwide income wherever they live. The same filing thresholds apply. Before deciding which form fits, separate four categories: citizen, green-card holder, substantial-presence resident and nonresident alien.
Substantial-presence residency needs at least 31 US days this year and a weighted 183 days (current year, plus one-third of last year, plus one-sixth of the year before).
Nonresident taxpayers with US connections
A nonresident alien with US-source income may need Form 1040-NR, depending on the income source, withholding and treaty position. Examples that need specialist review:
- Wages for work performed in the US
- US rental property
- US business activity
- US dividends
- Gains tied to US assets
Wages follow where the work is done. A US payer alone doesn't make wages US-source if you worked in Australia.
Foreign earned income and foreign tax credits
The foreign earned income exclusion (up to $130,000 for 2025, on Form 2555) and the foreign tax credit (usually Form 1116) can reduce US tax. Neither removes the filing test, because foreign earnings count before the exclusion. You can't claim a credit for tax on income you excluded.
The exclusion needs a foreign tax home plus bona fide residence or 330 full days abroad in 12 months. Pensions aren't eligible earned income.
The US-Australia treaty has a saving clause that preserves US taxation of its citizens and residents. It isn't a blanket filing exemption.
Currency and Australian income records
Convert Australian dollars to US dollars using a consistent, supportable method. The IRS yearly average rate for 2025 is A$1.551 per US$1, so divide A$ amounts by 1.551 when you use an annual average.
Australian wages, bank interest, investments, pensions and superannuation can all be treated differently by the US. Australian treatment doesn't dictate US treatment.
Deadlines and international compliance
For 2025 returns:
- 15 April 2026 is the regular deadline and the date to pay to avoid interest
- Qualifying taxpayers abroad get an automatic extension to 15 June
- Form 4868 extends filing to 15 October, requested before the automatic extension ends
- Form 1040-NR is due 15 April for wage earners with US withholding, otherwise 15 June
More time to file isn't more time to pay. Interest runs from 15 April. FBAR timing is separate from your return, so review all international forms early.
How to Check Your Filing Requirement
A practical five-step checklist
- Identify your status. Confirm your US tax status, filing status, age, dependency status and tax year.
- Collect every income source. Gather all information returns and records.
- Convert foreign amounts. Use a consistent exchange-rate method.
- Compare with the right test. Use gross income against the correct IRS table, not take-home pay.
- Check special triggers. Review self-employment, retirement distributions, Social Security, marketplace credits, foreign accounts and state filing.
Verify with official resources
Confirm the tax year first, because figures change. Then check these IRS resources:
- Do I need to file interactive tool
- Publication 501
- Form 1040 instructions
- Form 1040-NR instructions
The online tool is built for full-year citizens and resident aliens, not as a general nonresident test.
Get professional advice if any of these apply:
- You live in Australia
- You hold foreign accounts or pensions
- You claim treaty benefits
- You own US rental property
- You have self-employment income
- You can't tell whether Form 1040 or 1040-NR applies
Relevant VJM Global support
VJM Global prepares Form 1040 and Form 1040-NR returns for individuals, including Australia-based US taxpayers and foreign investors. Our tax and accounting professionals review income classification and cross-border reporting against your actual documents. The outcome depends on your facts, so no filing result is guaranteed.
Frequently Asked Questions
Do I need to file a federal tax return (Form 1040)?
It depends on your filing status, age, dependency status, gross income, income type and any special triggers. Run your numbers through the current IRS filing test.
What is the minimum income that requires you to file a Form 1040?
There's no universal minimum. For 2025, a single filer under 65 files at $15,750, while the married filing separately threshold is only $5. Check the figure for your status, age and dependency.
Do I need to file a Form 1040 if I have no income?
Usually not. But special circumstances can change that, such as nonresidents engaged in a US trade or business, or a separate foreign reporting duty. Filing can also recover withholding or refundable credits.
What is unearned income and does it affect your requirement to file Form 1040?
Unearned income is money not paid for work, such as interest, dividends, capital gains, rents and pensions. Dependants face much lower unearned-income triggers, such as $1,350 for 2025.
Who is not required to file a federal tax return?
People below the applicable gross-income threshold with no special trigger generally needn't file. Filing may still help claim a refund or credit.
Do I have to file a US Form 1040 if I live abroad (for example, in Australia)?
US citizens and green-card holders generally must still follow US filing rules abroad. Nonresident aliens may need Form 1040-NR instead. The same analysis applies if you live in Australia.
