That's the gap IRS Form 2120, the Multiple Support Declaration, fills. When no single taxpayer meets the ordinary support test, one eligible contributor may still claim the relative if the group together meets the rules.
For US citizens and residents living in Australia, the stakes are real: the IRS applies its filing rules abroad much as it does at home. This guide covers eligibility, support and waiver rules, filing steps, tax effects, common mistakes, and how Form 2120 differs from Australian ATO concepts.
Key Takeaways
- Form 2120 covers multiple-support arrangements only, not every dependent on a return.
- The person claimed must still be a qualifying relative under IRS rules.
- Signed waivers are separate from the form, and the claimant keeps them.
- Check the current-year thresholds before filing.
What Is IRS Form 2120?
Form 2120 is the IRS Multiple Support Declaration. It identifies the other eligible contributors who paid more than 10% of a relative's support and confirms the claimant holds their signed waivers.
The arrangement works only when the contributors as a group provide more than half of the person's support, and no single contributor provides more than half.
How it differs from other documents
- Form 1040: Dependants are listed in the Dependents section of your return. Form 2120 is an extra declaration attached to Form 1040 or 1040-SR.
- Form 8332: A custodial parent uses it to release a claim to a child. Form 2120 concerns qualifying relatives under multiple support. The two are not interchangeable.
What it does not do
Form 2120 does not:
- Prove the person is a qualifying relative
- Guarantee any credit
- Decide your filing status
Illustrative example
Three siblings support their father:
- Ana provides 40%
- Ben provides 35%
- Chloe provides 25%
Together they exceed 50%, and nobody alone exceeds half. Ana or Ben could claim him if the others who gave more than 10% waive. Chloe must waive as well, because her share is above 10%.
Who Is Eligible to Use Form 2120?
The dependant's tests
Under IRS Publication 501, the person must meet these qualifying-relative tests:
- Not be anyone's qualifying child (limited exceptions apply)
- Be an allowed relative, or live with you all year as a household member
- Be a US citizen, national, resident alien, or resident of Canada or Mexico
- Not file a joint return (except solely to recover withholding)
- Have gross income below the limit: US$5,300 for 2026 (US$5,200 for 2025)
Australian residence alone does not satisfy the citizenship or residency test.
Counting total support
Support includes food, lodging, clothing, education, medical and dental care, recreation and transport. Lodging counts at fair rental value.
Count amounts actually spent, not merely received. A parent's Social Security benefits count when spent on support. Publication 501 includes Worksheet 2 for the calculation.
Income taxes, life insurance premiums and funeral expenses are excluded.
The multiple-support rules
- The group together provides more than 50% of support.
- No single person provides more than half.
- The claimant provides more than 10%.
- Every other eligible contributor above 10% signs a waiver for that year.
Exactly 10% does not qualify someone to claim, and that contributor needs no waiver. In the IRS's own example, four siblings pay 45%, 35%, 10% and 10%. Only the first two can claim, and only one may.
What can block a claim
- The person is someone else's qualifying child
- The dependant files a disqualifying joint return
- The claimant is themselves claimable as another's dependant
- Public benefits supply most of the support
Someone claimable only through multiple support also isn't a head-of-household qualifying person, per Publication 501 (2025).
How to Complete and File Form 2120
Gather your documents
- Current Form 2120 (December 2025 revision)
- The relative's name and identifying number
- Each other contributor's name, SSN and address
- Support records and signed waivers
Fill in the form
Enter your return name, SSN, the calendar year and the relative's name. List each other eligible contributor paying over 10%, with name, SSN and address. If there are more than four, attach additional information.
Contributors sign separate statements giving the year, the relative's name, their own name, address and SSN, and their agreement not to claim. They don't sign the Form 2120 table.
Attach and retain
Attach Form 2120 to Form 1040 or 1040-SR. Do not file the signed waivers with the return. Keep them ready to produce if the IRS asks.
Individual Form 1040 is e-fileable. Confirm whether your tax software supports Form 2120 for the 2026 filing season, or file on paper.
A dependant who can't get an SSN normally needs an ITIN.
Filing workflow
- Confirm the relative meets every qualifying-relative test.
- Calculate total support and each person's share.
- Choose who claims for the year.
- Collect and keep the waivers.
- Complete Form 2120 and attach it to the return.
- Keep receipts, bank records, care invoices and housing records.
Worked hypothetical
Ana, Ben and Chloe agree Ana claims their father this year. Ben and Chloe each sign a waiver, which Ana files away. Ana attaches Form 2120 listing both. Next year the siblings may agree Ben claims instead, with new waivers. Rotation is a family arrangement, not automatic.
How Form 2120 Can Affect Your Tax Return
Form 2120 supports the dependant claim. It creates no exemption, credit or filing status by itself.
- Personal exemption: US$0 for 2026, as the IRS confirmed.
- Credit for other dependants: up to US$500, phasing out above US$400,000 (married filing jointly) or US$200,000 otherwise. The dependant must be a US citizen, national or resident alien.
- Medical expenses: itemisers may deduct costs above 7.5% of adjusted gross income.
- Dependent care credit: the adult must be unable to self-care and live with you over half the year, and the care must let you work.
Each benefit has its own conditions. Being claimed doesn't necessarily remove the dependant's own filing obligation.
Their standard deduction is limited to the greater of US$1,350 or earned income plus US$450 for 2026. Weigh both returns before filing.
Common Mistakes and When to Seek Help
Errors that cause problems
- Using Form 2120 in place of Form 8332, or as a general dependant list
- Assuming an ATO document replaces a US form
- Miscounting support or ignoring third-party contributions
- Listing the wrong contributors
- Missing waivers or using an outdated form
Duplicate claims often trigger IRS follow-up. The IRS may reject an e-filed return or send a CP87A notice. Don't attach unsolicited proof; respond only if the IRS asks.
Recordkeeping checklist
- Worksheet showing total support and each person's share
- Payment records for every contributor
- Signed waivers for the year
- Evidence of the relative's income and residency
- Notes on why the claimant qualifies
The IRS normally has three years to assess additional tax, so keep records at least that long. Review the return against the Form 2120 instructions and Publication 501, especially if contributors live in different countries.
When to get professional help
- Disputed claims or IRS notices
- Cross-border residency questions
- Amended returns
- Missing taxpayer identification numbers
- Unclear funding of support
VJM Global's US-compliant professionals prepare Form 1040 returns and help with IRS notices, including compiling documents and drafting responses. A professional review supplements IRS guidance but cannot guarantee a particular outcome.
Form 2120 and the ATO
Form 2120 is a US IRS declaration. There is no published ATO equivalent. Australian concepts are purpose-specific: a dependant for an individual return can be a spouse, a child under 21 who isn't a student, or a full-time student under 25.
Offsets such as the invalid and invalid carer offset have their own conditions. Check current ATO guidance for Australian purposes.
Frequently Asked Questions
Does having dependants affect your tax return?
It can. A dependant may affect eligibility for certain credits, deductions or filing statuses. The effect depends on their classification and whether you meet every current IRS requirement.
Which tax form shows my dependants?
Dependants are generally listed on Form 1040 or 1040-SR. Form 2120 is used only for qualifying multiple-support arrangements.
What are dependants on a tax form?
A dependant is a qualifying child or qualifying relative under IRS rules. Occasional financial help isn't enough; the person must meet the relationship, income, residency and support tests.
What is a dependant for the ATO?
Form 2120 isn't an ATO form. Australian dependant definitions differ and vary by purpose, so consult current ATO guidance.
When should I attach Form 2120 to my federal tax return?
Attach it when you claim a qualifying relative under a valid multiple-support arrangement. Confirm the current instructions first.
Do I send the signed waiver statements with Form 2120?
No. File Form 2120 and keep the waivers. Be ready to give them to the IRS on request.
