Who is the registered owner of the business? If only one of you, then at tax time all business income and expenses will be reported on a SCH C as a part of your joint tax return.
If both of you are the registered owners of the business, then the business is a separately taxable entity that has to file it's own completely separate 1065 partnership return. The partnership will then issue each owner a K-1, which each owner will need for completing the personal 1040 tax return. Doesn't matter that the owner's are married and filing joint either.
