What are common reasons taxpayers dispute an assessed IRS tax debt?

Taxpayers often challenge IRS assessments when they believe the amount is wrong. Common situations include:
– Substitute-for-Return (SFR) Assessments – The IRS files a return for the taxpayer using only third-party data, often overstating tax due by ignoring deductions or credits.
– Missed Audit Notices – Taxpayers didn\’t know they were audited because notices went to the wrong address or were never received.
– Automated Adjustments (e.g., AUR) – The IRS matches returns to third-party data and makes changes without a traditional audit, sometimes using incomplete or inaccurate data.