If you forgot to report 1099 income, the IRS already has a copy of every 1099 you received. Their system will match it to your return, and the gap will be flagged. Fix it now — before they contact you — to avoid the 20% accuracy penalty.

What to Do Right Now

Step Action Why
1 Log into irs.gov/account See what the IRS has on file for you
2 Identify the missing 1099 income Which 1099(s) you didn’t report
3 File Form 1040-X (amended return) Correct the mistake before the IRS catches it
4 Pay the additional tax owed Include payment with the amendment
5 Keep records of everything Proof you self-corrected

Types of 1099s the IRS Receives

Form Income Type Who Issues It
1099-NEC Freelance/contractor income ($600+) Clients / platforms
1099-MISC Rent, prizes, other income Various payers
1099-INT Bank interest ($10+) Banks
1099-DIV Dividend income ($10+) Brokerage firms
1099-B Stock/crypto sales Brokerages / exchanges
1099-G Unemployment, state refunds Government agencies
1099-R Retirement distributions 401(k)/IRA providers
1099-S Real estate sales Title companies
1099-K Payment platform income ($600+) Venmo, PayPal, Etsy, etc.
1099-DA Digital asset sales Crypto exchanges (new)

What Happens If You Don’t Fix It

Timeline What Happens
0-6 months after filing IRS processing; no contact yet
6-18 months CP2000 notice arrives — proposed additional tax + 20% penalty + interest
30 days after CP2000 If you don’t respond, proposed amount becomes final
60-90 days after final notice IRS issues CP3219A (statutory notice of deficiency)
After CP3219A IRS can levy bank accounts, garnish wages, file tax lien

Penalties: Self-Correcting vs. IRS Catching It

Scenario Tax Owed Penalty Interest
You amend before IRS notice Full tax on unreported income Usually $0 Yes (from original due date)
IRS sends CP2000 Full tax on unreported income 20% accuracy penalty Yes (from original due date)
You ignore CP2000 Full tax on unreported income 20% + potential failure-to-pay Yes (compounding)
IRS determines fraud Full tax + 75% fraud penalty Yes

Example: Forgot to Report $5,000 of 1099-NEC Income

Component Self-Corrected IRS Caught It
Additional income tax (22% bracket) $1,100 $1,100
Self-employment tax (15.3%) $765 $765
Accuracy penalty (20%) $0 $373
Interest (estimated, 1 year) ~$120 ~$120
Total $1,985 $2,358

Self-correcting saves $373 in this example — and avoids the stress of IRS enforcement.

How to Amend Your Return

Step Details
1 Download or e-file Form 1040-X
2 Add the missing income on the appropriate line
3 Recalculate your tax liability
4 Attach the 1099 you forgot to include
5 Explain: “Amending to include [1099-NEC/1099-K/etc.] income from [payer name] not included on original return”
6 Pay the additional tax with the amendment (check, Direct Pay, or EFTPS)
7 Track status at irs.gov/filing/wheres-my-amended-return

The Bottom Line

The IRS gets every 1099 you get — there’s no hiding this. Amend your return now, pay the additional tax, and you’ll typically avoid the 20% accuracy penalty. The longer you wait, the more interest accumulates and the higher the risk of formal IRS enforcement. This is one of the easiest tax mistakes to fix if you act quickly.

Related: I Forgot to File Taxes | I Forgot to Pay Quarterly Taxes