What filing status should I use for a common law marriage?

If you are living together in a common law marriage recognized in the state where you live or in the state where the common law marriage began, you are considered married and can file Married Filing Jointly, which usually is the filing status that gives you the biggest refund. However, not many people have a recognized common law marriage. The rules for recognizing a common law marriage vary by state and only a few states recognize common law marriages.