I received a notice saying in 2018 we didn't report ($200k ) from a company. I did list that already on my return as Other Self-Employed Income. What should I do?

[mikevbr]

I'm a 1099 employee and part owner of a company. At the time it was new, not existing for the entirety of 2018. The income I listed as other self-employed, and I received a notice today saying I reported $0 from the company when I made $200k  from them. There's now a bill for almost $100k with fat fees for this error, as they've added $200k  erroneously onto my 2018 earnings. What steps should I take?

[xmasbaby0]

TurboTax does not receive any information from the IRS or your state after your return was filed, so no one at TurboTax knows about a letter you received from the IRS or the state.

(what the letters from the IRS mean)

I GOT A LETTER FROM THE IRS   

https://ttlc.intuit.com/questions/3605673-i-got-a-letter-or-notice-from-the-irs

I AM BEING AUDITED

If you purchased Audit Defense:

https://ttlc.intuit.com/questions/2924451-i-bought-max-or-audit-defense-and-now-i-m-being-audited

AUDIT SUPPORT

TurboTax has a special phone number for help with IRS/state tax letters, which will be easier than going through regular Customer Support.   At the page below, click on the blue button that says "Get Help from TurboTax Support".  Then it will ask you what tax year is your letter.  Then it will ask you what the letter concerns. Then it will show you the phone number during posted business hours.

https://support.turbotax.intuit.com/irs-notice/audit-support/

If the resources above cannot help you enough then seek help from a qualified tax attorney in your area.  With over $100K at stake you need professional tax help.  This does not sound like a do it yourself situation.

[VolvoGirl]

Did you get any forms from the company?  Like a schedule K-1?  You probably should have.  You might have reported the income as self employment when it should have been entered as a K-1.  Or you were suppose to get a W2 for it.  

What tax return did you file for the company?  What kind of entity is it?  Is it a LLC or corp or partnership, etc?  Hopefully you filed the right business return for it like a 1120, 1120 S or 1065.  You might need to see an accountant to file the proper business taxes or fix them if you don't already have one.