What Are the Tax Steps for Common-Law Marriage Recognition by State?
If you and your partner meet your state’s requirements for a common-law (informal) marriage, the tax and financial consequences can be immediate and significant. Below are practical, state-focused steps to confirm recognition and manage taxes correctly. These steps are written from the perspective of a financial professional who has advised clients through residency changes, benefit claims, and amended returns.
1) Confirm whether your state recognizes new common‑law marriages and the effective date
Not all states permit the creation of new common‑law marriages today. A few states (for example, Texas and Colorado) still recognize informal marriages when couples meet the state’s criteria. Your first step is to check official state sources or consult an attorney. For federal tax purposes, the IRS treats you as married if your marriage is valid under the law of the state where you live or where you were married (IRS Publication 501).
- Action: Search your state government site for “common-law marriage,” “informal marriage,” or “declaration/registration of informal marriage.”
- Why it matters: If the state recognizes your relationship as a marriage, you and your spouse must generally use a married filing status for federal returns for the year in which you were married (your marital status on December 31 determines the filing status for that tax year).
Source: IRS Publication 501 (Filing Status) — https://www.irs.gov/publications/p501
2) Gather and preserve proof that you meet the state’s criteria
States that recognize common‑law marriages typically require evidence of: (1) mutual agreement or intent to be married, (2) cohabitation for a period (if specified by state law), and (3) holding yourselves out to the public as married. Documentation reduces risk if your filing status is later questioned.
Suggested documentation:
- Joint bank and credit card accounts and statements
- Joint property deeds or mortgage documents
- A written, sworn affidavit of common‑law marriage or a declaration/registration filed with a county clerk (if offered by the state)
- Shared utility bills and which list both names at the same address
- Insurance policies or beneficiary designations naming each other
- Testimony or affidavits from friends/family or employer records showing use of a shared surname or introduction as spouses
In my practice, clients who kept a simple packet of dated, joint documents avoided long audits and were able to update benefits faster.
3) If available, use a state declaration or registration process
Some states allow couples to file a declaration or register an informal marriage with a county clerk. Filing a formal, state‑recognized declaration creates clear official proof and simplifies tax and benefits administration.
- Action: If your state offers registration, file the form and keep certified copies. If not, request a court declaration or a notarized affidavit if you expect disputes (for example, before an employer recognizes a spouse for benefits or when estate issues may arise).
4) Update payroll withholding and employer benefits
Once your state recognizes the marriage, update your employer(s) with the appropriate paperwork to change tax withholding (Form W-4) and enroll in spousal benefits (health insurance, retirement beneficiary forms). Employer plans and payroll systems typically rely on state law and documentation to grant spousal access.
- Action: Provide employer HR with a certified declaration or other proof of marriage to change benefits and withholdings.
- Timing: Changes to W-4 affect only future paychecks; ensure your employer processes changes promptly to avoid underwithholding.
5) Choose the correct federal filing status for the tax year
Federal filing status depends on your marital status on December 31 of the tax year. If your common‑law marriage is valid before year end under the state law where you live or where the marriage was formed, you must file as Married Filing Jointly or Married Filing Separately for that tax year (IRS Pub. 501).
- Married Filing Jointly is often more tax‑efficient, but there are cases (large medical expenses, separate liabilities) where Married Filing Separately may be preferable. See our guide to Married Filing Jointly for details and comparisons.
Internal resource: Filing checklist for newly married couples — Filing Taxes After Marriage: First-Year Checklist.
6) Understand state income tax treatment and residency quirks
State rules differ widely. Some states that do not allow new common‑law marriages still recognize those established elsewhere (this is called recognition by comity). If you formed a common‑law marriage in a recognizing state and later moved to a non‑recognizing state, the marriage often remains valid for federal and many state purposes — but that can be a complex area.
- Action: Check the residency and filing rules for each state where you file. If you file multiple state returns, ensure you apply the correct filing status for each jurisdiction.
Internal resource: Correcting Filing Status — useful if you need to amend previously filed returns due to incorrect marital status.
7) Consider amending prior federal or state returns if you were entitled to different treatment
If your relationship met the legal standard for marriage in years you filed incorrectly, you may be able to file an amended return (Form 1040‑X for federal returns). The IRS generally allows refunds claimed within three years of the original return date or two years after the tax was paid, whichever is later. Keep in mind statute of limitations and state timelines may differ.
- Action: Consult a tax professional before filing amended returns; I frequently review prior returns with clients to determine if amending will produce a refund after accounting for potential audit risk.
Source: IRS guidance for Form 1040‑X and refund statute
8) Update estate planning, beneficiary designations, and government benefits
A recognized common‑law spouse may have rights to Social Security benefits, survivor benefits, and inheritances. Update wills, beneficiary designations, powers of attorney, and health care proxies.
- Social Security: The SSA recognizes marriages valid under state law for benefit claims; check SSA guidance when planning for survivor’s or spousal benefits.
Sources: Social Security Administration (marriage and benefits guidance); Consumer Financial Protection Bureau (estate and survivors planning resources)
9) If a dispute arises, look for declaratory relief or a court judgment
When a state’s recognition of an informal marriage is disputed (for example, after a death or during a divorce or benefit claim), parties often seek a court declaration of informal marriage. A court order provides strong proof for tax agencies and benefit administrators.
- Action: If you anticipate a contested claim (inheritance, survivor benefits, or tax refunds), consult an attorney early. Court actions can produce retroactive recognition or clarify dates of marriage.
Common mistakes and how to avoid them
- Filing as married without state recognition or proper proof. Always confirm that the state recognizes your union before changing your filing status.
- Assuming moved states nullify a valid common‑law marriage. In many cases, a marriage valid where formed remains valid elsewhere for federal tax purposes.
- Failing to collect contemporaneous documentation. Joint files, joint accounts, and a notarized affidavit go a long way.
Practical examples from practice
Example 1 — Moving between states:
I worked with a couple who formed a common‑law marriage in Texas and then moved to a state that didn’t create new informal marriages. Because their marriage was valid in Texas before the move, they were able to file federal returns as married and claim spousal benefits. They saved several thousand dollars on federal taxes in the first year they filed jointly.
Example 2 — Amending returns:
A client discovered after a spouse’s death that they were recognized as common‑law spouses in the state where they lived. We reviewed three prior years of returns and successfully filed amended returns that produced a modest refund after applying credits they had been ineligible for as single filers.
Quick checklist before you file
- Confirm whether your state recognizes common‑law marriage or whether your marriage is recognized by comity.
- Collect dated, joint documents and, if available, file a declaration of informal marriage.
- Update employer and payroll forms (W‑4) and benefit enrollments.
- Choose the correct federal and state filing status based on your marital status on December 31.
- Consult a tax professional about amending prior returns or pursuing a court declaration when status is unclear.
Resources and authoritative references
- IRS Publication 501: Filing Status — https://www.irs.gov/publications/p501
- IRS Form 1040‑X guidance: https://www.irs.gov/forms-pubs/about-form-1040x
- Social Security Administration: Marriage and benefits information — https://www.ssa.gov/planners/marriage/
- Consumer Financial Protection Bureau: Planning and legal checklists — https://www.consumerfinance.gov
Professional disclaimer: This article is educational and reflects guidance current as of 2025. It is not legal or tax advice. State laws change and individual circumstances vary; consult a licensed tax professional or attorney before making filing or legal decisions.
If you want a tailored checklist for your state, tell your tax advisor the state where the marriage was formed and your current residency; that information determines which statutory rules and filing steps apply.
