IRS Letter 4800C is a notice the IRS sends if they believe you underreported income on your tax return. It comes from their Automated Underreporter (AUR) program, which compares what you reported to what employers, banks, and other payers reported to the IRS.
Why You Received It
The letter usually means there is a mismatch between your return and the IRS’s records. Common causes include:
- A missing or incorrect Form 1099 or W-2
- Overlooked investment income, such as dividends or stock sales
- Social Security, retirement distributions, or unemployment compensation not reported correctly
What Happens Next
The letter will show the IRS’s proposed changes to your tax return, including any additional tax, penalties, or interest. You generally have 30 days to respond.
If you agree:
- Sign and return the response form
- Pay the balance due or set up a payment plan
If you disagree:
- Send documentation such as W-2s, 1099s, or brokerage statements to support your return
- The IRS will review your evidence and may adjust or confirm their assessment
What Happens if You Ignore It
If you do not respond, the IRS will assess the additional tax automatically. Penalties and interest will continue to accrue, and the account could be sent to collections.
What You Should Do
Read the letter carefully to identify the income in question. Compare the IRS’s figures with your records. Respond before the deadline, even if you need to request additional time. Keep copies of everything you send.
W-2 and 1099 Prior Year Corrections
We specialize in 1099 e-file corrections and prior year corrections.
Call (480) 706-6474 today to get started and make sure your filings are accurate.