Registered domestic partners and same sex married couples can find themselves at a tax crossroads come filing time. The difference between federal and state recognition of same-sex marriage and domestic partnerships can create challenges that married heterosexual couples do not face.
That's because, as of 2014, not all states recognize marriages between same sex couples. Domestic partners and same sex spouses, therefore, can submit only state tax returns based on the rules of the state where they are domiciled. Also, even if domestic partners can file a joint state tax return, they can only file individual federal tax returns unless they are legally married. How you handle state tax forms depends on which community property state you call home.