I’ve received several calls from a computer that says “This is IRS. We have been trying to reach you. This is your final notice before filing suit.” The voice sounds very close to the voice on the IRS’s menu – the voice that thanks you for calling and advises you how long your estimated wait time is.
Please note that the IRS does not call you via robo-dialer. When you speak to an actual IRS employee, they will identify themselves as Agent (name) and give you their badge number.
The telephone numbers that popped up on my caller ID were 619-625-0169 and 424-350-8761 – they will probably call you if you’re in the 214 area code.