An erroneous refund is considered an underpayment of tax on the date made. An assessment of a deficiency arising out of an erroneous refund may be made at any time within two years from the making of the refund. If part of the refund was induced by fraud or misrepresentation of a material fact, the assessment may be made at any time.
If a joint income tax return is filed by a husband and wife, an order of assessment may be a single joint notice. If the commissioner has been notified by either spouse that that spouse's address has changed and if that spouse requests it, then, instead of the single joint notice mailed to the last known address of the husband and wife, a duplicate or original of the joint notice must be sent to the requesting spouse at the address designated by the requesting spouse. The other joint notice must be mailed to the other spouse at that spouse's last known address. An assessment is not invalid for failure to send it to a spouse if the spouse actually receives the notice in the same period as if it had been mailed to that spouse at the correct address or if the spouse has failed to provide an address to the commissioner other than the last known address.