Common law marriage is established by proof that you have cohabited (lived together), represented to others that you are married and had an agreement to be married. The agreement can be inferred from the other two elements. Texas Family Code section 2.401. Common law marriage, otherwise known as informal marriage, may also be established by filing a sworn declaration of and registration of informal marriage with the County Clerk of your county, pursuant to Texas Family Code 2.402. There is a rebuttable presumption of no marriage unless a suit is commenced to prove the marriage before the second anniversary that the parties “separated and ceased living together”.