Did anyone else receive a letter 4883C - and is finding it impossible to get through to the IRS?

[revmkschue-129]

I received the letter in May 2021.  Every time I call I can't even get put on hold due to "extremely high call volume"

[Critter-3]

https://www.irs.gov/individuals/understanding-your-letter-4883c-or-6330c

What happens if I cannot verify?

If we can’t verify your identity over the phone, we will ask you to schedule an appointment and bring the documents listed above to your local IRS office to verify in person.

[revmkschue-129]

The problem is NOT that they can't verify my identity over the phone. The problem is that I cannot even get through to a human being on the phone. I am concerned that this is a seemingly impossible task

[Critter-3]

That is an issue as the IRS is understaffed and overwhelmed with work.   Try just before 7am your time zone.