Do RDPs have to file with Community Property Allocation in filing separately is better for them?

[danekronick]

if filing separately is a better return

[KrisD]

For the Federal return, the couple can only file Single or Head of Household.

For the state, if you are in a community property state, it depends on which state that is.  

A state like CA which is both a community property state AND recognizes Registered Domestic Partners, YES you will need to use the allocation worksheet. 

It won't really matter which way you file since you need to allocate the income regardless. If one partner has a debt, the other taxpayer might see filing separately advantageous to not be liable for the repayment of the loan, but the same could be accomplished by filing an  8379 "Injured spouse" form which frees the "innocent taxpayer" from the debt liability of the other. 

But if the couple live in a community state like Texas, they would not use the community property worksheet and only file separately. 

https://ttlc.intuit.com/replies/3301795