1. Once I forgot to give my tax guy my Fidelity 1099 stuff. When I found the damn thing a year later (in the wrong folder) I wrote the IRS. About a month later I got an IRS notice about it. Anyway I wrote that I hope I could avoid some certain large penalty, given that I initiated the contact letting them know of the error. Fixed, no penalty beyond the interest charges. And of course I had to pay the additional tax on the additional income
2. My elderly Dad in his last 2 years neglected to take his IRA RMD distributions. There's a 50% penalty for failure to take required RMD distributions, meaning for example if he was supposed to take $10,000 RMD distribution and didn't take any, then he has to take the distribution and pay the resulting tax on the increase in taxable income, PLUS 50% of $10,000 = $5,000 penalty.
My sister and I wrote a long record about how medically on the edge he was in the last 2 years with all his ailments and tons of prescriptions -- result: penalty waived
3. Something about some interest on an H Bond IIRC but might have been something else. Anyway I had a phone conversations with an IRS agent who very patiently and expertly explained the whole thing.
4. Back when I was on the ACA (Affordable Care Act, Obamacare), they complained that the estimated income (AGI) that I had used to get the ACA subsidies was far below what was subsequently reported to the IRS (they actually expect you to guess your income nearly 2 years in advance, sigh).
I explained in an overly long letter (that was probably unnecessary in all its excruciating detail) that actually my estimate of my AGI was quite accurate -- listing about 7 different sources of income -- EXCEPT for one thing -- I took a large Roth conversion at the end of the year that I had not anticipated doing when I made the estimate (Roth conversions add to one's AGI and taxable income). I never heard back 😊
I can't think of any encounter I've had with the IRS that was unfair or the person was a jerk or anything like that.
Those letters often have the agent's direct phone and email address where you can also contact them. You shouldn't have any problem. They are really very friendly and willing to help you.
Not this one, but I'd expect that in their response to my upcoming response, given that a human IRS agent, and not a bezerko computer, looked at it.