How many years do you have to live together for a common law marriage?

Where the myth comes from

Probably from old presumption-of-death statutes, which allowed a missing spouse to be declared dead after seven years of absence, and from decades of repetition in movies and television. No US state has ever made cohabitation alone for a set time into a marriage. New Hampshire's inheritance rule, which asks for three years of cohabitation and public acknowledgment before a partner's death, is the closest thing to a time requirement, and it applies only for inheritance.

What courts actually look for

• A present, mutual agreement to be married — not an engagement, not a plan for the future. Both partners must have meant it.
• Living together in a recognizing state while that agreement was in force.
• Public conduct consistent with marriage: joint tax returns filed as married, the same surname, a spouse listed on insurance, health care or pension forms, a joint lease or deed describing the couple as husband and wife, and references to “my husband” or “my wife” to family, employers and neighbors.

Length of the relationship is evidence of the agreement, not a substitute for it. Twenty years of cohabitation without holding out has repeatedly been held not to create a marriage; a shorter relationship with consistent documentation has.

Two examples

A couple in Texas lives together for eight months, tells everyone they are married, files a joint tax return and puts each other on their health insurance as spouses. That can be a valid informal marriage. Another couple lives together in Illinois for fifteen years, owns a house together and raises children, but never marries. They are not married, because Illinois does not create common law marriages at all — no matter how long they stay together.

What cohabitation alone gives you

Very little by default. No automatic property rights in assets titled to the other partner, no spousal inheritance, no right to make medical decisions, no spousal support on separation, and no survivor benefits. Parents have the same rights and duties toward their children whether or not they are married, but an unmarried father may need to establish paternity formally. Couples who want protections without marrying generally use a cohabitation agreement, joint ownership documents, wills, beneficiary designations, health care proxies and durable powers of attorney.

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Why the timing still matters

Although there is no minimum duration, dates matter in other ways. In states that abolished common law marriage, the relationship must have met all the requirements before the cut-off date. In Texas, a claim must generally be brought within two years after the couple separates. And when a common law marriage exists, its start date affects which property is marital and how long the marriage lasted for spousal support purposes — questions that are often disputed because no wedding date exists.

Ending one

A valid common law marriage ends the same way as any other marriage: by divorce or death. Simply moving out does not end it, even after many years apart. Someone who later marries another person without a divorce may find the second marriage invalid, which can affect inheritance and benefits for years.

Why this comes up

Usually at the worst moment — when a partner dies without a will, when a long relationship ends and one person expected marital rights, or when an application for spousal benefits is denied. If you are unsure of your status, gather documents from the relationship and ask a family law attorney in the state where you lived together; the answer depends on that state's law and on your paperwork, not on the calendar.

A quick self-check

Ask three questions. Did we live together in a state that recognizes common law marriage, or before its cut-off date? Did we both agree that we were married, not just that we would marry one day? Did we consistently present ourselves as married, especially on official documents? If the answer to any of the three is no, there is very likely no marriage, however long the relationship has lasted.