Filing Claim for Refund of PT Excise Tax?

[Guest ggbrock]

Does anyone know whether Form 843 or Form 5330 is the appropriate form to file for a refund of an overpaid excise tax that relates to a Code 4975 violation, i.e., a late transmittal of contribution to a 401(k) plan?

I understand the Form 843 is the form generally used for refunds, but the instructions to the Form 5330 indicate that it is the appropriate form to be used to file a refund for an overpayment of excise taxes (but does not include a "claim for refund" form to attach to it.)

Any help is much appreciated.