I think this is a Tax Fraud number. It was a voice automated call and the voice sounds like its computer generated. It didn't leave any info other than to call the number back to say that it's the IRS. I think the IRS would send a formal letter.
I often receive this call from this same number and wish someone was on the other line so I could blow my whistle! Really, IRS working on a national holiday... Don't f'ing think so.
Report the Calls to the real IRS here:
•report the incident to the Treasury Inspector General for Tax Administration at 800-366-4484.
•You can also file a complaint with the Federal Trade Commission at FTC.gov. Add "IRS Telephone Scam" to the comments in your complaint.
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Do consider maybe getting a call blocking device or phone.. You can google them and many are around $60.00 or so.