A Registered Domestic Partner (RDP) is someone who is part of a legally recognized domestic partnership under state law but is not considered married for federal income tax purposes. While many states provide domestic partners with rights and benefits similar to those of married couples, federal tax rules generally treat RDPs differently than married spouses.
Understanding the difference between federal and state treatment is important because your filing status may not be the same on your federal and state tax returns.
Federal Tax Filing Rules for Registered Domestic Partners
For federal income tax purposes, registered domestic partners are generally not treated as married.
As a result:
- You cannot file a federal return as Married Filing Jointly (MFJ).
- You cannot file a federal return as Married Filing Separately (MFS).
- Each partner must typically file a separate federal return as:
- Single, or
- Head of Household (HOH) if all Head of Household requirements are met.
For example, if one partner maintains a home for a qualifying child and meets the other IRS requirements, that partner may be eligible to file as Head of Household rather than Single.
Federal Tax Benefits Generally Unavailable to RDPs
Because registered domestic partners are not considered married under federal tax law, certain tax benefits available to married couples generally do not apply.
These may include:
- Married Filing Jointly filing status
- Married Filing Separately filing status
- Spousal IRA contribution rules
- Certain federal estate and gift tax provisions that apply only to legally married spouses
This difference can affect tax planning, retirement contributions, and other financial decisions.
State Tax Filing Rules for Registered Domestic Partners
State treatment of registered domestic partnerships varies widely.
Some states recognize domestic partnerships and allow partners to file state income tax returns similarly to married couples. Other states provide limited recognition, while some do not recognize domestic partnerships at all.
Because of these differences, it is common for an RDP to:
- File a federal return as Single or Head of Household, and
- File a state return using a different filing status.
States That Allow Joint State Filing for RDPs
The following jurisdictions generally treat registered domestic partners similarly to married couples for state income tax purposes and allow joint or separate state filing options:
- California
- Connecticut
- Hawaii
- Nevada
- Oregon
- Vermont
- Washington
- District of Columbia
If you live in one of these jurisdictions, you may be able to file a joint state return even though you must file separate federal returns.
States That Recognize Domestic Partnerships but Do Not Allow Joint State Filing
Some states recognize domestic partnerships, civil unions, or similar legal relationships for limited purposes but do not allow joint state income tax filing.
These states may include:
- Colorado
- Illinois
- Maine
- Maryland
- Massachusetts
- New Jersey
- New Mexico
- New York
- Wisconsin
In these states, partners typically file state returns as Single or Head of Household, depending on the state's rules and their individual circumstances.
Because state laws can change, taxpayers should review current state filing requirements before filing.
States That Do Not Recognize Domestic Partnerships
Some states do not provide domestic partnership recognition for state income tax filing purposes.
Examples include:
- Alabama
- Alaska
- Arkansas
- Delaware
- Idaho
- Kansas
- Kentucky
- Mississippi
- Montana
- Nebraska
- New Hampshire
- North Dakota
- Ohio
- Oklahoma
- Rhode Island
- South Carolina
- Tennessee
- Utah
- West Virginia
- Wyoming
In these states, domestic partnerships generally do not affect state income tax filing status.
Special Rule: Mock Federal Returns
Some states require registered domestic partners to prepare a mock federal return when completing their state income tax return.
This often applies in states such as:
- California
- Oregon
- Washington
What Is a Mock Federal Return?
A mock federal return is a federal return prepared solely for state tax calculations.
The return:
- Uses a filing status such as Married Filing Jointly or Married Filing Separately, as required by state law.
- Is not filed with the IRS.
- Is used only to determine information needed for the state return.
Your actual federal return must still be filed using the filing status allowed under federal law, typically Single or Head of Household.
Head of Household Considerations for RDPs
Being in a registered domestic partnership does not automatically prevent you from qualifying for Head of Household status.
You may qualify if you:
- Are considered unmarried for federal tax purposes,
- Pay more than half the cost of maintaining a home, and
- Have a qualifying child or other qualifying dependent who lived with you for the required period.
Head of Household status generally provides:
- A higher standard deduction than Single filing status
- More favorable tax brackets
Because the rules can be complex, it's important to review all qualification requirements carefully.
Common Filing Situation
A common scenario for registered domestic partners looks like this:
Federal Return
- Partner A files Single or Head of Household
- Partner B files Single or Head of Household
State Return (if state recognizes RDPs)
- Partners may file jointly or separately according to state law
This creates a difference between federal and state filing statuses, which is normal for many registered domestic partners.