Married filing separately

[mooretax]

Taxpayers are California residents. They are married but want to file separately. They live
together all year.

Can they file separately without splitting half of their income?

Is there any exemption for not splitting the income while living together?

[taxea]

read the California instructions

[Gary2]

California allows married couples to elect separate property treatment via prenuptial and even post-nuptial agreements. I'd advise seeing an attorney if that's the path they want to follow.

But first find out why, and make sure they're doing it for good reasons. Many people jump to MFS when Injured Spouse would be a better option.