When a corporation does business partly within and partly without this State or uses its capital partly within and partly without this State, the amount of the license fee provided for in Section 12-20-50 must be apportioned in accordance with the ratio prescribed for income tax purposes in the taxable year preceding the year in which the annual report is filed. The minimum license fee, however, may not be apportioned.
S.C. Code § 12-20-60