"The Social Security Administration will freeze the SSN of a person who has died to prevent fraud. Once they do this it is not possible to e-file a tax return that includes a deceased spouse. "
I guarantee this is not your problem if your spouse died during the tax year of the return submitted for processing. For example, if your spouse died in 2021, the number will not be locked until 2023 or later. This allows survivors time to settle the estate and meet any related tax obligations.
