the interest is probably because the IRS was tardy in issuing you your 2020 refund. the amount would have been included in the refund. the actual payor is the US Treasury, not the IRS. Address and EINS are never needed for 1099-int's or even most other items unless taxes are withheld. in most cases, where no withholding the address and EIN are not transmitted as part of the e-file.
.
