Credits or refunds after period of limitation

A refund of any portion of an internal revenue tax shall be considered erroneous and a credit of any such portion shall be considered void— If made after the expiration of the period of limitation for filing claim therefor, unless within such period claim was filed; or In the case of a claim filed within the proper time and disallowed by the Secretary, if the credit or refund was made after the expiration of the period of limitation for filing suit, unless within such period suit was begun by the taxpayer. For procedure by the United States to recover erroneous refunds, see sections 6532(b) and 7405. Any credit against a liability in respect of any taxable year shall be void if any payment in respect of such liability would be considered an overpayment under section 6401(a).