Colorado is one of only a few states which still recognize common law marriage. This concept is fraught with public misunderstanding.
The elements of a common law marriage are:
Obviously, there is no difficulty if both parties agree that they were married at common law. The problem arises where one party dies and the survivor is seeking death benefits, or where one person claims there is a marriage and the other denies it (usually in the context of a divorce). The second and third criteria listed above often become determinative of the dispute, as there is usually not a dispute as to the “living together” requirement.
In resolving such disputes, Courts look to objective facts to determine the parties’ subjective intent. These may include filing joint tax returns, having children, using the same last name, listing someone as a spouse for insurance purposes, etc. The key inquiry is whether they generally conducted themselves as a married couple.
The traps inherent in this situation are patent. Someone who thought he/she was married may not be determined to be married, and someone who thought he/she was not married may be determined to be married. The obvious solution is to actually register your marriage with the County if that is your intent, and to not try to finesse benefits (health insurance, lower tax rates, etc.) for someone else who is not your spouse.
We also suggest that people who intend to live together for an extended period of time without intending to be married actually put that in writing so that there will be no confusion.