Ga. Code § 48-7-35
If any corporation or nonresident shows by any method of allocation other than the processes or formulas prescribed by this chapter that another method reflects more clearly the income attributable to the trade or business within this state, application for permission to base its return upon the other method shall be considered by the commissioner. The application shall be accompanied by a statement setting forth in detail with full explanations the method the taxpayer believes will more clearly reflect its income from business within the state. If the commissioner concludes that the method of allocation and apportionment submitted by the taxpayer is in fact inapplicable and inequitable, he shall reject the application and shall so notify the taxpayer. Failure to receive the commissioner's notice shall not operate to relieve the taxpayer from liability for not filing the return on its due date utilizing the allocation and apportionment method prescribed by this chapter.
OCGA § 48-7-35