800-829-8310

Yes it is..I later called the IRS number and they checked us out. Was told to report it to tigta.gov

I guess its a real number, but after being on hold for an hour i was getting down to my last  minutes i had remaining on my phone plan so i hung up.   All I I wanted was a time extension.  I complied in good faith by calling the number.  As a resul, 95% of my phone minutes were squeezed out of my phone plan.  Being on hold for over an hour is unacceptable by any standards.  I will make sure i include this in the supporting documentation i am sending late to the IRS.

Perhaps you should have called the actual IRS @ their contact # on their official website.

I received the same

Exactly! I just got my federal return less than a month ago which was $7,000 and today I received a letter with the same phone number saying that I owed $3000! If I owed that right now, why didn't they take their $3000 and give me a $4000 return? Duh, a scam for sure!

I received a letter from IRS and a phone call saying  legal action is going to be taken against me regarding my 2018 tax return. The letter was signed by Glen Kilkenny. Does Glen Kilkenny work with IRS?  Should this letter have a Govt. seal on it? is this a scam/

I bet I know who could answer that for you.  The actual IRS.  Why I bet you could even go to their website and look up their known, published phone number and call them.

I got letter from them with this number 800 829-8310 twice saying that I owe taxes for 2018

Its a real number ..it is on the IRS site.
https://www.irs.gov/tax-professionals/practitioner-priority-service-r

I got a letter with same number to call .. is it fraud how do I find out  if it's true or not it said I have to pay at the end of the month

Yes, I received a letter in the mail for a proposed refund & I wanted to make sure they send it to me not my deceased husband.  I called and they had all the info. Then I got nervous because when I got the call back number it had SPAM? IRS & didn't think twice about it not just having SPAM? but why did it have IRS name appearing too. Well, she had all info including social security & address but I wouldn't give her mine because I said I am lerry now about the call. She had all info date mailed & amount but still felt off. Oh well, I will see if I am really a dumb blonde by calling 1-800-829-8310 & having someone call me back on my phone. Now what do I have to do to correct this mistake?

This letter states my husband and I owe 3,999 back from 2019 on vehicles that repossessed 5 to 7 years ago. Looked up this number it's not legit.

I'm not sure how you would owe taxes on repo'd vehicles in the first place.  Possibly they sold them for less than the loan balance, but then they would have had to send you a 1099-C which you would have had to report on your 1040 for that year.