Individual income tax and corporate franchise tax refunds modifications; interest calculated on payments of estimated tax inclusion in refund requirement

This bill modifies Minnesota's tax refund process to include interest on estimated tax payments when taxpayers receive refunds. It directly affects individual income tax filers and businesses (like S corporations, partnerships, and corporations) that paid estimated taxes during the year and later overpaid their tax liability. The key change requires refunds to include interest calculated from the date each estimated tax payment was made until either the refund claim date or the original tax due date. This interest uses the same rate applied to taxes paid to the state under existing rules. The change applies to refunds for taxable years beginning after December 31, 2024.