You may file joint, separate, or combined separate Delaware returns. If you choose to file as combined separate, you are in fact filing two separate returns for you and your spouse which have been combined on the same form for convenience.
Generally, separate or combined separate returns will be beneficial if both spouses have Delaware adjusted gross income that is more than $9,400.
If you choose to file separate or combined separate returns, both you and your spouse must use either the standard or itemized deduction. Also, you each report only your own income, personal credits, deductions, and one half of the income from securities, bank accounts, real estate, etc., which are titled or registered in joint names.
If you qualify as certain married persons living apart, you may file as Head of Household on your Delaware return.