The persons who are most favored by both the North Carolina and federal income tax laws are married couples in a "traditional" relationship, where one spouse works outside the home and the other spouse does not have a separate income. The persons least favored by the income tax codes are married couples in which each spouse has about the same income. Persons in a gay or lesbian relationship are somewhere in between these two extremes. In general, a gay or lesbian couple in which one partner has a substantially greater income than the other will pay higher taxes than a married couple with the same income. Where both partners make about the same income, there is no disadvantage and possibly an advantage in not having to pool incomes for tax purposes.
Unlike a married couple, one member of a gay or lesbian couple may itemize deductions while the other takes the standard deduction. If deductible items such as mortgage interest are paid by the itemizing partner, there may be a great tax savings.