This case addresses the issue of whether the IRS mailed an estate tax deficiency notice to the estate’s last known address if the IRS mailed the notice to the address shown on the estate tax return, despite having notice that there was a new address for the executor. The deficiency notice was returned by the postal service marked “Attempted Not Known.” The IRS did not issue another deficiency notice after the original one was returned because the deadline for issuing a deficiency notice to the estate had passed.

The Tax Court held that the IRS knew at the time the deficiency notice was issued that the estate’s address had changed, and that the IRS therefore failed to use reasonable care and diligence in mailing the notice to the estate’s last known address. The deficiency notice was held to be invalid, and, accordingly, the estate’s motion to dismiss for lack of jurisdiction was granted.