Colorado sets no time requirement for a common law marriage. There is no six-month rule, no seven-year rule, no minimum cohabitation period written into any statute or court decision. A couple can form a valid common law marriage in a single day if the right elements are present, and a couple who have lived together for thirty years may never have formed one at all. Duration is not the test.
What Actually Creates the Marriage
Colorado’s framework comes from case law rather than a single statute. The Colorado Supreme Court’s 2021 decision in Hogsett v. Neale refined the standard originally set in 1987’s People v. Lucero. Under the current test, a common law marriage forms when two things happen together: the couple mutually agrees to enter the legal and social institution of marriage, and they then act in ways that show that agreement to the outside world.1Justia. In re Marriage of Hogsett and Neale – 2021 – Colorado Supreme Court Decisions
The agreement element is simple to state and hard to pin down. Both people must genuinely intend to be spouses, not just romantic partners or roommates sharing a lease. No specific words are required, and nothing needs to be written. But a one-sided belief that you are married does not count. Both parties have to be on the same page at the same time.
The conduct element is where disputes usually land. A court looks at whether the couple’s behavior, taken as a whole, shows an intent to share a life together as spouses in a committed relationship of mutual support and obligation. The Hogsett court deliberately avoided a rigid checklist, noting that “the manifestation of the parties’ agreement to marry need not take a particular form.”1Justia. In re Marriage of Hogsett and Neale – 2021 – Colorado Supreme Court Decisions Hogsett also replaced the old “husband and wife” language from Lucero with gender-neutral terms, confirming that same-sex couples can form common law marriages in Colorado on the same footing as opposite-sex couples.
Because the test is about agreement and conduct, time is only relevant to the extent it helps show those things. A weekend is enough if the agreement and the outward signs are genuinely there. Decades are not enough if they aren’t.
Who Can Form One in the First Place
Time is not a requirement, but eligibility is. Under C.R.S. ยง 14-2-109.5, for any common law marriage entered into on or after September 1, 2006, both parties must be at least 18 years old, and the marriage must not be otherwise prohibited by law.2Justia. Colorado Revised Statutes Title 14-2-109.5
Prohibited marriages include unions where one party is already legally married to someone else, or where the parties are too closely related by blood. If either person is under 18 or already married, no amount of shared bank accounts, joint tax returns, or matching last names will create a valid common law marriage. The 18-year minimum here is stricter than Colorado’s ceremonial marriage age, which allows 16- and 17-year-olds to marry with parental consent and a court order.
Why Time Still Comes Up in Practice
If someone later claims a common law marriage exists and the other party disagrees, a court has to decide. The person asserting the marriage carries the burden of proof by a preponderance of the evidence, meaning more likely than not.1Justia. In re Marriage of Hogsett and Neale – 2021 – Colorado Supreme Court Decisions That is where length of relationship starts to matter, not as a legal threshold but as practical proof.
The Lucero decision identified two factors that carry particular weight: living together and having a reputation in the community as a married couple.3Justia. People v Lucero – 1987 – Colorado Supreme Court Decisions Longer cohabitation and a longer-standing reputation make both easier to establish. Beyond those two, courts weigh a range of conduct:
- Joint federal or state tax returns filed as a married couple. Colorado’s Department of Revenue allows common law spouses to file jointly on the state return if they filed jointly at the federal level.4Department of Revenue – Taxation. Common-Law Marriage
- Shared finances, including joint bank accounts, joint credit cards, and co-owned property.
- Use of a shared last name, introductions as “my husband” or “my wife,” and mail addressed to both as a married couple.
- Estate planning that names each other as beneficiaries on life insurance, retirement accounts, or wills.
- Testimony from friends, family, neighbors, or coworkers who understood the couple to be married.
No single item is required and no single item is decisive. A couple with joint tax returns but no shared last name can still be common law married. A couple sharing a last name but filing separately might not be. As the Lucero court put it, “any form of evidence that openly manifests the intention of the parties that their relationship is that of husband and wife will provide the requisite proof.”3Justia. People v Lucero – 1987 – Colorado Supreme Court Decisions
So while a day is legally enough, a day rarely produces enough visible evidence to prove the marriage if someone later contests it. That is a proof problem, not a timing rule.
Making It Easier to Prove
Because no license or ceremony is involved, Colorado has no central registry of common law marriages. When you need to prove the marriage to an employer, insurer, hospital, or government agency, the burden is on you to produce something. The simplest step is a common law marriage affidavit.
Several Colorado county clerk and recorder offices accept affidavit forms that both spouses sign and have notarized, attesting to their mutual agreement to be married. In Larimer County, the recording fee is $16, with notary services available at the courthouse for $5. The affidavit does not create the marriage; your agreement and conduct do that. It gives you a recorded document you can point to later.
Build the rest of your paper trail steadily. File joint tax returns if you qualify. Add your spouse to insurance policies. Use consistent names on leases, deeds, and financial accounts. The more places your married status appears in writing, the easier the marriage is to prove if it is ever questioned, whether by a benefits administrator, a probate court, or the other spouse.
Once Formed, It Only Ends by Divorce
The flip side of having no minimum duration is worth understanding before you decide you want to be considered common law married. A common law marriage carries the same legal weight as a ceremonial marriage. It can only end through a formal divorce. You cannot simply stop calling each other spouses, move apart, or start filing separate taxes and treat the marriage as over. Until a court dissolves it, it exists.2Justia. Colorado Revised Statutes Title 14-2-109.5
The divorce process is the same as for any other marriage. The court divides marital property and debts, decides spousal maintenance where appropriate, and addresses parental responsibilities for any children. The filing fee for a divorce petition in Colorado is $260, with fee waivers available for people who cannot afford the cost.5Colorado Judicial Branch. List of Fees
A relationship that qualifies as a common law marriage on day one is a marriage on day one, with all of the rights and all of the exit costs that follow. The absence of a time requirement cuts both ways.