A dependent can be a qualifying child or a qualifying relative for tax purposes, and the Internal Revenue Service defines “relative” somewhat loosely. But the rules for whom you can claim are still intricate enough to make "qualifying" somewhat difficult. Your partner might be your dependent as a “qualifying relative,” but only if they meet four specific criteria: residency, income limits, marital status, and support needs.
The Residency Test
Your partner must actually live with you in your home to qualify as your dependent. They can’t maintain their own residence, not even for a week or a month. Their address must be your address throughout all 365 days of the tax year.
Temporary absences are okay, however. Your partner might be hospitalized, incarcerated, or serving in the military. Maybe they've taken an extended vacation. That's fine, as long as they intend to return to your home after these events—and they actually do so.
Some qualifying relatives don’t actually have to live with you, but this rule is reserved for literal relatives, which your partner is not.
Your parent is an example of a relative who doesn't have to live with you.
You can't claim your partner as a dependent for that tax year if they move in with you in March, but you can claim them in the next year if they're still living with you on January 1, and they remain with you all through that year—assuming they meet the other qualifying rules.
Income and Support Factors
Your partner must effectively live with you because they can’t afford to live on their own, and this can’t be just an objective opinion. The IRS imposes actual income limits.
They can’t earn more than $4,300 as of the 2020 tax year—the tax return you'll file in 2021. This figure is adjusted for inflation, so it can be expected to increase periodically. It used to be equal to the amount of the personal exemption that was available each year, but the exemption itself has been reduced to zero through 2025 under the terms of the Tax Cuts and Jobs Act (TCJA).
This is your partner's gross income, not their taxable income after claiming various deductions. Certain tax-exempt sources of income, such as Supplemental Security, don’t count toward the total, but unearned income such as interest or dividends does.
You must also pay for more than half of their yearly support: their share of the rent or principal mortgage payment, utilities, food, clothing, and other “essential” expenses. Paying 50% of these costs isn't sufficient. It must be 51% or more.
You can’t claim your partner as a dependent if $600 of your monthly budget is attributable to them and they contribute their limited income of $345 a month, because $345 represents more than 57% of their $600 share of your living expenses. But you can claim them if $1,000 of your budget is dedicated to their support, because now they're paying $345, and you’re paying $655 a month, which comes out to more than 65%.
If Your Partner Is Married
Your partner must file a separate married return, not a joint return with their spouse if they're still legally married to someone else because their divorce isn’t final yet. Neither your partner nor their spouse can owe taxes if they file separate married returns.
An exception exists if they're filing jointly simply to claim a refund of all taxes withheld from their pay.
The IRS additionally says that your relationship with your partner must be “legal” in the state where you reside. This doesn’t mean you have to get married or enter into a recognized domestic partnership, but it could be a problem if your partner is still legally married to someone else, and you live in a state where it’s illegal to cohabit with a partner who’s married to someone other than you.
A Few Other Rules
Your partner must also be a U.S. citizen, national, or resident alien, or a resident of Canada or Mexico. Of course, establishing residency in those countries would probably mean they're not living with you full-time, so as a practical matter, they wouldn't be your dependent.
Finally, no one else can claim your partner as a dependent. The Internal Revenue Code provides that only one taxpayer can claim the same individual as a dependent per tax year.
Advantages of Having a Dependent
It used to be that you could slash $4,050 off your taxable income in the form of a personal exemption for each dependent you could claim in 2017. Then the TCJA eliminated personal exemptions from the tax code beginning in 2018. The TCJA remains in effect through 2025.
The TCJA is set to "sunset" or expire in December 2025, but it's possible Congress could renew some or all of its terms, so there's no guarantee that personal exemptions will come back at that time.
You might still qualify for other tax breaks related to having a dependent, however. The TCJA also introduced the Credit for Other Dependents in 2018, worth $500. Tax credits are particularly beneficial because, unlike tax deductions, they come directly off any tax you owe to the IRS, dollar for dollar. Deductions only reduce your taxable income.
Qualifying as Head of Household
Having a dependent can also qualify you for the advantageous head of household filing status.
You’d qualify as head of household anyway if you're already supporting a child or other dependent, but otherwise, claiming your partner as a dependent can increase your standard deduction to $18,650 as of the 2020 tax year. The standard deduction for single filers is just $12,400.
These figures increase to $12,550 for single filers and to $18,800 for head-of-household filers in the 2021 tax year, because they're indexed for inflation.
There are a few other rules for qualifying as a head of household in addition to having at least one dependent. Many of them mirror the same rules for claiming your partner as a dependent anyway, however:
- You must pay more than 50% of your home’s expenses.
- You can’t be married to your partner, or “considered married” to anyone else, either. This means that if you and your spouse aren't yet legally divorced or separated by court order, you haven't lived together at any point during the last six months of the year.
This six-month rule would disqualify your partner as your dependent anyway, assuming they weren't living with you and your spouse at the same time.
The IRS provides a withholding calculator to help you figure out whether all of your dependents are really your dependents for tax purposes.
Should You Get Married?
Your standard deduction would hike even more if you and your partner were to get married and file a joint married return—up to $24,800 in the 2020 tax year. But you’d be gaining a spouse and losing a dependent, which could cost you some of those other tax breaks available to taxpayers with dependents.
You can't claim your spouse as a dependent as of 2020, although you could claim a personal exemption for them under certain isolated circumstances through 2017.
It all comes down to your unique personal circumstances. If you’re on the fence about getting married, consult with a tax professional and/or an attorney to make sure you understand all the implications. You also might want some tax advice to make absolutely sure that your partner qualifies as your dependent.