Yes, the IRS does recognize common law marriage. Under Revenue Ruling 58-66, if your common law marriage is valid under the law of the state where it was formed, the IRS treats you exactly like a ceremonially married couple for every federal tax purpose: filing status, deductions, credits, and estate tax benefits. That recognition sticks even if you later move to a state that doesn’t allow common law marriage. If your state says you’re married, so does the IRS, and you’re required to file your federal return that way.
How the IRS Decides You’re Married
The IRS has no independent definition of marriage. It defers to the law of the state or territory where the marriage was entered into. Publication 501 puts it plainly: you are “considered married” for the entire tax year if you are living together in a common law marriage recognized either in the state where you now live or in the state where the marriage began.1Internal Revenue Service. Publication 501 (2025), Dependents, Standard Deduction, and Filing Information Your status is fixed as of December 31: if you meet your state’s requirements on that date, you’re married for the whole year.2Office of the Law Revision Counsel. 26 U.S. Code 7703 – Determination of Marital Status
The rule has stood since 1958 and was reaffirmed in Revenue Ruling 2013-17, which confirmed the same principle applies to same-sex couples. A valid common law marriage formed in a state that permits one is recognized federally regardless of where the couple lives now.3Internal Revenue Service. Revenue Ruling 2013-17
Where a Common Law Marriage Can Start
Only a handful of jurisdictions still let couples form a new common law marriage. As of 2026, those are Colorado, Iowa, Kansas, Montana, Oklahoma, Rhode Island, Texas, Utah, and the District of Columbia. Rhode Island and Oklahoma recognize them through case law rather than statute.
Several states abolished common law marriage but still honor unions established before a cutoff date:
- Alabama: before January 1, 2017
- Florida: before January 1, 1968
- Georgia: before January 1, 1997
- Idaho: before January 1, 1996
- Indiana: before January 1, 1958
- Ohio: before October 10, 1991
- Pennsylvania: before January 1, 2005
- South Carolina: before July 24, 2019
If you formed a valid common law marriage in one of these states before its cutoff, it remains valid, and a move to another state doesn’t erase it. New Hampshire is a narrow exception: it treats couples as married only after one spouse dies, and only for inheritance and survivor-benefit purposes, so it does not create a lifetime marriage for federal income tax filing.
One myth worth killing: cohabitation alone, whether for seven years, ten years, or longer, does not create a common law marriage anywhere. States that allow it require mutual agreement to be married, holding yourselves out as spouses, and legal capacity to marry.
How You Have to File
Once you’re in a recognized common law marriage, you must file federally as a married person. Single is off the table. Your choices are Married Filing Jointly or Married Filing Separately.4Office of the Law Revision Counsel. 26 U.S. Code 6013 – Joint Returns of Income Tax by Husband and Wife A joint return makes both spouses jointly and severally liable for the full tax bill, so the IRS can collect the entire amount from either of you.
For 2026, the standard deduction is $32,200 for Married Filing Jointly and $16,100 for Single. Joint brackets are also wider: the 22% rate starts at $50,400 of taxable income for a single filer but not until $100,800 for joint filers.5Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
The Head of Household Exception
A common law spouse can sometimes file as Head of Household instead of Married Filing Separately. The IRS considers you unmarried for this purpose if all four are true: you file a separate return, you paid more than half the cost of keeping up your home for the year, your spouse did not live in the home during the last six months of the year, and a qualifying child lived with you for more than half the year.2Office of the Law Revision Counsel. 26 U.S. Code 7703 – Determination of Marital Status This matters most for separated common law spouses who haven’t yet divorced.
What Recognition Actually Gets You
Filing jointly opens up credits and deductions that shrink or disappear on a separate return. You can pool medical expenses and charitable donations, claim education credits, and take the full child tax credit. The Earned Income Tax Credit is the sharpest example: couples filing separately are generally blocked from the EITC unless they lived apart from their spouse for the last six months of the year.6Internal Revenue Service. Who Qualifies for the Earned Income Tax Credit (EITC)
Federal recognition also carries over past income tax. Property left to a surviving spouse qualifies for the estate tax marital deduction, removing it from the taxable estate.7Office of the Law Revision Counsel. 26 U.S. Code 2056 – Bequests, etc., to Surviving Spouse Gifts between spouses are exempt from gift tax. Common law spouses also qualify for Social Security spousal and survivor benefits, provided they can document the marriage. Ceremony or no ceremony, the tax benefits are identical.
Proving It if the IRS Asks
There’s no federal common law marriage certificate, so if the IRS questions your filing status, you’ll need to show that a valid common law marriage exists under the relevant state’s law. Useful evidence includes:
- Joint financial records: bank accounts, property deeds, car titles, insurance policies naming both of you
- Shared household documents: leases, mortgage statements, or utility bills at the same address
- Public representations: social media, holiday cards, school records, or anywhere you referred to each other as spouses
- Prior joint tax returns, which are strong evidence that you held yourselves out as married
- Written statements from friends, family, or clergy who consider you married
Gathering this early is much easier than reconstructing it during an examination.
If You’ve Been Filing as Single
Some couples don’t realize they meet their state’s common law requirements; others file as Single to avoid a higher combined bill. Filing as Single or Head of Household when you’re legally married is an incorrect return, and the IRS can assess additional tax, interest, and accuracy-related penalties on top.
You can correct prior years by filing Form 1040-X. Switching from separate returns to a joint return is allowed within the amendment window, but the reverse generally isn’t: once you’ve filed jointly, you can’t move to separate returns after the filing deadline.8Internal Revenue Service. Instructions for Form 1040-X To claim a refund on the amendment, file within three years of the original return’s due date or within two years of paying the tax, whichever is later.9Internal Revenue Service. File an Amended Return
You Can’t End It Informally
This is where couples most often go wrong on their taxes. You can enter a common law marriage without paperwork, but you can’t leave one that way. It has the same legal weight as any other marriage, and ending it requires a formal divorce. Moving apart, dropping a shared last name, or telling people you’ve split does not dissolve it.
Until a court issues a divorce decree or a decree of separate maintenance, the IRS still treats you as married. You continue filing as Married Filing Jointly or Married Filing Separately, or as Head of Household if you meet all four conditions above. Single is not an option.1Internal Revenue Service. Publication 501 (2025), Dependents, Standard Deduction, and Filing Information