So, in Texas, common law marriage is defined as
Common law marriage, also known as marriage without formalities or informal marriage, is a valid and legal way for a couple to marry in Texas. There are three elements of a common law marriage according to Texas law. Per Chapter 2.401 of the Texas Family Code, you must have all three parts in order to have a common law marriage.
- You have "agreed to be married."
- You have "lived together in this state as husband and wife."
- You have "represented to others" that you are married.
Represented to others means, you tell other people you are married, rather than saying "boyfriend" or "fiancee" or "partner", but actually say "this is my spouse" or "this is my husband or wife" when talking to neighbors, friends, banks or other businesses that you have relationships with, etc.
If you do not meet the conditions for common law marriage, then you are single, and you file as single. One of you could possibly file as head of household if you have a qualifying person, usually a child dependent.
If you do not meet the conditions for common law marriage now, but you want to get married, you just have to agree, and tell someone else. Then you could file as married filing jointly. However, a common law marriage has the same legal force as a church marriage--you have to do everything in your life from now on as if you are legally married (because you are) and you can't split up without a full legal divorce.
