The IRS permits only legally married couples to file tax returns as “married, filing jointly.” Since the national legalization of same-sex marriage in 2015, it does not matter whether these unions are straight or gay, but they do need one thing in common as far as the IRS is concerned – a marriage license. It does not matter, in most instances, how long a couple has been together, whether they have children or if they consider themselves married. An exception may apply to unmarried couples who live in the handful of states that still recognize common law marriages. Otherwise, both individuals must file as single taxpayers.
TL;DR (Too Long; Didn't Read)
Although you may be able to claim your girlfriend as your dependent if requirements are met, you will usually need to be married to her to file a joint tax return.
Unmarried Couples Living Together and Taxes
Older people may recall when unmarried people living together were thought to be “living in sin.” It’s a quaint notion these days, but decades ago those who cohabited for a length of time and were otherwise in a quasi-marital situation might find their union considered marriage under common law. Today, the following states still recognize common law marriage under certain circumstances: Colorado, Iowa, Kansas, Montana, New Hampshire, Oklahoma, Rhode Island, South Carolina, Texas and Utah. New Hampshire generally recognizes the marriages for inheritance purposes only. Washington, D.C. also recognizes common law marriage.
Some states once had common law marriage statutes on their books but have since abolished such recognition. Some states, such as Alabama and Georgia, may still recognize common law marriages for those couples whose cohabitation preceded the date the laws were changed.
There is no magic number of years in any of these states that automatically make a union a common law marriage. Instead, a court examines various factors including the length of the partnership, the extent to which the couple presented themselves as married, and whether they shared finances and household expenses or kept all such matters separate. Check with your state laws to understand the legal requirements for a common law marriage. If you're filing taxes as married when you're not, you may be liable for tax penalties or even criminal penalties if you do so fraudulently.
Claiming Her as a Dependent
While you probably can’t file jointly with your girlfriend on your tax return, you may be able to claim her as a dependent. That may be the closest you can come to "unmarried filing jointly" status. To qualify, she must have earned less than $4,150 in taxable income in 2018, lived with you for the entire year as a household member, and is not claimed on anyone else’s return as a dependent. You must also contribute at least half of her support for the entire year. Your girlfriend must also possess U.S. citizenship or permanent legal status. An exception is made for Mexican or Canadian residents.
Registered Domestic Partners
A number of states had civil unions and registered domestic partnerships before the legalization of same-sex marriage. For same-sex couples, such states may have automatically converted these couples status to marriage after same-sex marriage was legalized on either the state or national level. Some states, such as California, allow domestic partnerships if one member of the couple is aged 62 or older, so they will not lose certain benefits should they remarry. However, such domestic partnerships are not recognized on the federal level as the same as marriage, and these couples cannot file as married, filing jointly.
Tax Law Changes for 2018
If you are claiming an unmarried partner as a dependent in 2018, they can make up to $4,150, as opposed to $4,050 for the 2017 tax year. This amount is regularly adjusted for inflation.
- IRS: Choosing the Correct Filing Status
- NPR: No, You're Not In A Common-Law Marriage After 7 Years Together
- National Conference of State Legislatures: Common Law Marriage By State
- IRS: Publication 501 Cat. No. 15000U Exemptions, Standard Deduction, and Filing Information
- AL.com: Common Law Marriage in Alabama Ending Jan. 1, 2017
- AARP Foundation Tax Aide: Dependent Qualification Calculator