Q: What is the timeline for state tax refunds, and at what date does the state have to pay penalties for late refunds? -- Vernon Kersey, Alpharetta A: State law says interest is not subject to being paid by the Department of Revenue for a Georgia individual income tax refund return until 90 days after the filing date of the final return showing an overpayment or 90 days after the due date of the final return, whichever is the later date.