Generally, when you live in a community property state and you and your spouse file separate returns, you must split any community income and deductions evenly between the spouses. However, different rules apply for the assessment of self-employment tax.
Per IRS Publication 555 Community Property, on page 7:
Sole proprietorship. With regard to net income from a trade or business (other than a partnership) that is community income, self-employment tax is imposed on the spouse carrying on the trade or business.
When one or both spouses has self-employment income, they each must report half of the income on their return. However, the spouse who has the self-employment income should pay the full amount of self-employment tax on their earnings and the spouse who does not have self-employment earnings should not pay any self-employment tax on those earnings.
To make the self-employment tax adjustment:
The program will now calculate the correct amount of self-employment tax for each spouse.
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