Quick checklist: First steps after you receive an IRS notice

  • Read the notice carefully and note the notice code, date, and any deadlines.
  • Verify the notice is genuine (see steps below to spot scams).
  • Gather the tax return, supporting forms (W-2, 1099s), bank records, and prior correspondence.
  • Decide whether you can respond yourself or should engage a tax pro.
  • Respond by the deadline, using the methods the notice specifies (mail, phone, or online).

The rest of this article explains what notice codes mean, how the IRS uses them, practical response templates, and professional strategies I use in practice to resolve notices efficiently.

Why notice codes matter

Notice codes are not arbitrary. They direct your attention to the IRS’s specific concern and usually prescribe the next step. For example, CP2000 indicates income or payment data on file differs from your return and invites a response (see IRS CP2000 page: https://www.irs.gov/individuals/cp2000). A CP503 is a payment reminder that escalates collection steps if ignored. Treating a notice as a generic letter is risky; the code tells you whether the issue is urgent, technical, or remediable through documentation.

Authoritative IRS guidance on interpreting notices is available at “Understanding Your IRS Notice or Letter” (https://www.irs.gov/individuals/understanding-your-irs-notice-or-letter) and provides explanations for many common codes. For appeals and collection rights, IRS Publication 556 remains a key resource (https://www.irs.gov/pub/irs-pdf/p556.pdf).

How to verify a notice is legitimate

Scams and phishing attempts mimic IRS notices. Follow these verification steps before sharing sensitive information or making payments:

  • Confirm the letter has a notice code and an IRS contact number. Genuine notices will include a notice number and account-specific details.
  • Check your tax account online at IRS.gov/Account (requires identity verification) to see if the IRS shows the same notice or balance.
  • The IRS first contacts taxpayers by mail — the IRS will not initiate tax-related contact by email, text message, or social media.
  • If the letter demands immediate payment via gift cards or third-party apps, assume it’s a scam and report it to the Treasury Inspector General for Tax Administration (TIGTA) and the IRS.

If you’re uncertain, the page “What to Do When the IRS Calls: Verifying Identity and Avoiding Scams” on FinHelp offers step-by-step actions to confirm legitimacy: https://finhelp.io/glossary/what-to-do-when-the-irs-calls-verifying-identity-and-avoiding-scams/.

Common notice codes and typical actions

Below are several frequent codes and the typical response I recommend in practice. This is illustrative, not exhaustive.

  • CP2000 — Income discrepancy: Compare amounts on the notice to your return and supporting forms (W-2, 1099). If the notice is correct, sign the response and pay the amount or request an installment agreement. If incorrect, provide documentation and a clear explanation within the timeframe given (usually 30 days). (IRS CP2000: https://www.irs.gov/individuals/cp2000)

  • CP11 / Math Error Notice — IRS adjusted tax due to a math error: Review the adjustment and supporting math. If you agree, pay or set up a payment plan. If you disagree, respond with the corrected math and supporting documentation. FinHelp has a guide on math errors and fixes: https://finhelp.io/glossary/what-triggers-an-irs-math-error-adjustment-and-how-to-fix-it/.

  • CP503 / CP504 — Payment reminders: These are escalation notices. If you can pay, do so or contact the IRS to arrange a payment plan. If you can’t pay in full, request an installment agreement or explore other relief options.

  • CP91 — Final notice of intent to levy: This notice is urgent. Immediately contact the IRS or a tax professional to halt collection action, request a collection due process hearing, or secure a temporary hold by entering a payment arrangement.

  • Letter 525 / Notice of No Return Filed: If you receive a notice about an unfiled return, file the missing return promptly to stop penalties from growing. For guidance, see FinHelp’s article on handling unfiled-return notices: https://finhelp.io/glossary/handling-an-irs-notice-about-unfiled-returns-steps-to-take/.

Practical response framework (use this as a template)

1) Read and record: Note the notice code, date received, IRS contact info, and deadline.

2) Recreate the facts: Pull the tax return in question, wage statements, 1099s, bank records, and any other documents the notice references.

3) Decide your position:

  • Agree with the notice — sign and return the response form if provided and pay or set up a payment plan.
  • Partially agree — pay the undisputed portion and explain why you contest the remainder.
  • Disagree — prepare a written rebuttal with copies (not originals) of supporting documents.

4) Document your response: Keep a dated copy of everything you send and use certified mail for physical submissions when appropriate.

5) Follow up: Check your IRS online account or call the IRS using the number on the notice to confirm receipt and next steps.

Example response paragraph (for disputes):

“I respectfully dispute the adjustment stated in Notice CP2000 dated [date]. Enclosed are copies of my [W-2 for 20XX / 1099-NEC / bank statements] showing the correct amount of income reported on my Form 1040 for tax year [year]. Please update my account accordingly or provide further explanation of any remaining discrepancy.”

Keep the tone factual and concise; emotional language rarely helps.

Deadlines, penalties, and appeals

Notices often include specific response deadlines (commonly 30 or 60 days). Missing deadlines can result in default assessments, additional penalties, interest, or collection actions such as liens or levies. If you disagree with an IRS determination, you have appeal rights. Publication 556 explains how to request an appeal and taxpayer rights during collections (https://www.irs.gov/pub/irs-pdf/p556.pdf).

If collection action has already begun, you can request a Collection Due Process hearing or submit an Offer in Compromise if you meet strict eligibility criteria (IRS Offer in Compromise: https://www.irs.gov/individuals/offer-in-compromise).

When to hire a tax professional

Engage a licensed tax professional or enrolled agent when:

  • The notice threatens collection actions (levy, lien, or passport certification).
  • The liability is large or the facts are complex (business income, multi-state issues, significant adjustments).
  • You suspect identity theft or fraud on your account.
  • You prefer representation in communications or appeals.

In my practice, early engagement with a tax pro often saves money and stress. A professional can draft concise responses, negotiate installment agreements or offers in compromise, and represent you in appeals. If the notice relates to potential criminal exposure, consult a tax attorney.

Recordkeeping to avoid future notices

  • Keep W-2s, 1099s, receipts for deductible expenses, and records of payments for at least three years; seven years if you file for a loss from worthless securities or bad debt.
  • Reconcile third-party forms (1099s) with your bookkeeping annually to catch missing income early.
  • File amended returns (Form 1040-X) when correcting mistakes discovered after filing.

Common mistakes taxpayers make

  • Ignoring the notice, assuming it’s a mistake.
  • Sending an emotional or defensive response without documentation.
  • Sending originals of documents instead of copies.
  • Failing to follow specific response instructions (for example, sending the wrong address or failing to include the notice stub).

Final tips and resources

  • Keep your response short, factual, and well-documented.
  • Verify notices with your online IRS account before making payments.
  • Use certified mail for important submissions and keep proof of delivery.
  • If you can’t pay in full, ask about installment agreements or short-term delay in collection.

Useful resources:

Professional disclaimer

This article provides educational information about IRS notice codes and practical response strategies. It does not replace personalized tax advice. For case-specific guidance, consult a qualified CPA, enrolled agent, or tax attorney.

Author note

After 15+ years helping taxpayers resolve IRS notices, the most common win I see is prompt documentation and calm, direct communication. The IRS often accepts clear corrections when you provide timely, organized evidence.