I paper filed an amendment for my 2020 tax return which was processed with Single status. Because unavailability of ITIN, I could not include my spouse in the 2020 tax filing.
ITIN for a spouse was received in March 2022. For the 2020 amended tax return IRS send notice - LTR 105 C that:
"We can't allow your claim for changing the filing status to married filing joint."
"The ITIN for the added Secondary taxpayer has an assigned date of March 2022. We can't process the request to change filing status to married filing joint for the tax year 2020 with this assigned date. Since the filing status remains Single the claim for a lower tax rate and the recovery rebate credit can't be allowed."
I haven't claimed any stimulus credit in the amended 2020 tax. It's just a filing status change from single to married filing joint with a lower tax for joint filing.
Please suggest the next steps if you have faced this situation.