If you live in a community property state, your husband could be legally if a lawsuit were to be filed against the business whether or not you filed married filing jointly or married filing single. SEE BELOW.
Whether you and your spouse are liable for each other's debts depends mostly on where you live. In the handful of states with "community property" rules
, most debts incurred by one spouse DURING the marriage are owed by both spouses. But in states that follow "common law
" property rules, debts incurred by one spouse are usually that spouse's debts alone, unless the debt was for a family necessity, such as food or shelter for the family or tuition for the kids.
The community property states are Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin. (In Alaska, spouses can sign an agreement making their assets community property, but few people choose to do this.)
In community property states, most debts incurred by either spouse DURING the marriage are owed by the "community" (the couple), even if only one spouse signed the paperwork for a debt. The key word here is DURING the marriage.
If you do not live in a community property state, the answer to your question would be no, since your husband is not a partner in the business, he would not be liable if a legally liable if a lawsuit was filed against the business.
If the two of you file separately, your husband cannot claim you as an exemption.