Unreported income notice: how a mismatch happens and how to reply

Why these notices arrive

The IRS compares your return with forms that employers, clients, banks and platforms send in. When a form shows income your return does not, the IRS may propose a change. A CP2000 is the best-known version. The IRS says it proposes changes because third-party information on file does not match the return, that it is not a bill, and that the change may increase tax, decrease it or leave it unchanged. It does not call it an audit.

How gig and contractor forms cause mismatches

If a client paid you as a contractor, expect a Form 1099-NEC. The IRS says that form reports payments to nonemployees for services in a trade or business, while employee wages go on Form W-2. The IRS also says gig income must be reported even if it was part-time or temporary, and even if it was not reported on a 1099-K or 1099-NEC or was paid in cash, property or virtual currency.

So mismatches come from several directions: a form you never received, one that arrived after you filed, two forms covering the same payment, or income you forgot. Each has a different fix.

Example: a designer with three clients

Picture a designer who filed using her bank deposits and later gets a notice. One client sent a 1099-NEC that she forgot to count; a second client's form double-counted an invoice that was also paid through a payment app; the third payment was a refund of her own expense. Her response would agree with the first item, explain the second with invoices and statements, and show the third with the original receipt.

Notice what makes that work: each form is matched to a document, one at a time.

Read these parts of your notice first

Before you gather anything, find the facts that control your next steps.

• The response date printed on the notice
• Which forms and amounts the IRS says are missing
• The explanation of any proposed change
• How to respond (mail, fax or online) and where to send documents

Your options

Most people end up in one of three places. If the IRS is right, you agree and follow the instructions for paying or arranging payment. If the IRS is partly right, you agree with some items and document the rest. If the IRS is wrong, for example because the income is not yours or was already included, you disagree and explain with records.

For a CP2000 specifically, read the IRS notice page and the CP2000 pages on this site. The response date is the one on your notice; do not rely on a general number.

Tax effects to keep in mind

Added business income can also change self-employment tax. The IRS describes it as Social Security and Medicare tax, figured on Schedule SE, with rates and a wage base that change each year; check the IRS page for current figures. A corrected return or response may therefore change more than one line.

Putting your response together

IRS Audit Defense Pro is software that helps you organize your facts and draft a response letter you review and send yourself; it is not a law firm, CPA or enrolled agent. For a mismatch notice, organize the forms the IRS lists, mark which you agree with, and attach the documents that support the rest. Keep copies of everything you send and a record of how you sent it.

Frequently asked questions

Sources

• IRS: Understanding your CP2000 series notice
• IRS: Gig economy tax center
• IRS: Forms and associated taxes for independent contractors
• IRS: Self-employment tax (Social Security and Medicare taxes)

Related guides

• You received a CP2000. Here is how to read it and replyA CP2000 is a proposal, not a bill and not an audit.
• CP2000 response letter sample: when part of the proposed change is wrongA CP2000 response letter identifies the notice, goes through each proposed item, says what you accept and what you dispute with a reason, lists your enclosures, and is signed.
• Crypto and Form 1099-K IRS inquiries: what the letter is askingIRS questions about digital assets or a Form 1099-K usually ask you to reconcile what was reported with what is on your return.
• Schedule C audit: supporting your business income and expensesA Schedule C audit tests the income and expenses of your sole proprietorship.
• Letter to the IRS disagreeing with a notice: a general templateA disagreement letter identifies the notice by number and date, lists which items you dispute and why, points to enclosed documents, and asks for a written reply.
• How to get your IRS tax transcriptsThe fastest route is usually your IRS Online Account, where you can view and download transcripts.