Common-Law Marriage in Illinois: An Illusion Illinois does NOT recognize common-law marriage. This is a crucial point for anyone living in or considering moving to Illinois. While some states allow couples to be legally recognized as married without a formal ceremony and marriage license, Illinois requires a formal marriage to establish a marital relationship and its associated rights and responsibilities. ⚠ Important: Living together for any length of time in Illinois, even decades, does *not* create a common-law marriage. Illinois abolished common-law marriage in 1905. Why Understanding This is Crucial Misunderstanding the lack of common-law marriage recognition in Illinois can have significant legal and financial consequences, especially if a relationship ends. Without a legal marriage, individuals may face challenges in: ⚡ Property Division: Illinois marital property laws do not apply to unmarried couples. There's no automatic right to ...