CP20 Notice Explained (What It Means + What To Do Next)

Quick answer: An IRS CP20-series notice is usually an audit-by-mail “initial contact” letter. It means the IRS is questioning one or more items on your return, and they want proof before they release the part of your refund/overpayment that’s tied to those items.

In plain English: the IRS is saying, “We see an item on your return that might not be allowed. Show us documents that prove you qualify.” This page walks you through what a CP20 notice is, why you got it, what to send, what not to send, and how to protect yourself while you respond.

What is a CP20 notice?

The CP20 notice series (you might see versions like CP 20 E, CP 20 F, CP 20 G) is a letter that typically comes from a correspondence audit unit (an audit handled through the mail).

Most commonly, it shows up when your tax return shows an overpayment/refund, but the IRS wants to verify that you’re entitled to a credit, deduction, or other item before they release the questioned amount.

Takeaway: A CP20 is not “just a reminder.” It’s an audit-style request for proof.

Does a CP20 mean you’re being audited?

Yes—functionally, a CP20 is part of an audit (examination) by mail. That sounds scary, but it doesn’t automatically mean you did anything wrong. The IRS reviews a lot of returns this way, especially when a return includes credits, deductions, or income items that don’t match what the IRS has on file.

If you want the bigger picture on “audit fear,” you can read this too: Does an IRS letter mean an audit?

Takeaway: Treat it seriously, but don’t panic. This is usually a “prove it” letter.

Why did you get a CP20 notice?

CP20 notices usually happen when the IRS sees something on your return that looks unallowable or needs verification. Common triggers include:

  • Credits that require eligibility proof (examples: certain education credits, dependent-related credits, etc.)
  • Deductions that need documentation (examples: certain business expenses, large itemized deductions, etc.)
  • Income mismatches (what you reported vs. what payers reported to the IRS)
  • Identity/return integrity checks (not always, but sometimes documentation helps clear it)

Important: The CP20 letter should tell you exactly what item(s) they’re questioning. Don’t guess. Use the letter as your checklist.

Takeaway: The CP20 isn’t random. It’s tied to a specific item on your return.

What the IRS is asking for (and what they are NOT asking for)

What they usually want

The IRS typically wants documents that prove eligibility. That might include things like:

  • Forms, statements, or official records that support the credit/deduction
  • Receipts and invoices (when relevant)
  • Proof of payments (bank/credit card statements showing the transaction)
  • Proof of dependency or residency (only if your notice is about a dependent-related item)
  • Letters or records from third parties (schools, childcare providers, employers, etc.)

What they do NOT want

  • Original documents (send copies)
  • A “box of paper” with no explanation
  • Unrelated documents “just in case”
  • Handwritten notes that aren’t backed by proof

Takeaway: Send targeted proof that matches the exact item listed in the CP20—nothing more, nothing less.

What to do next (step-by-step)

Step 1: Read the CP20 letter like a checklist

Circle or highlight:

  • The tax year
  • The item(s) being questioned
  • The deadline
  • The address or fax number for your response
  • Any reference number or examiner/contact info

Takeaway: Your best response is built directly from what the letter asks for.

Step 2: Gather proof that directly supports the questioned item

Think like this: “If someone who doesn’t know me reads these pages, would they clearly see why I qualify?”

Takeaway: If the proof doesn’t connect clearly, it won’t help.

Step 3: Create a short cover letter (simple, clean, helpful)

A cover letter keeps your package from becoming a mess. Keep it short:

  • Your name and last 4 of SSN (or the taxpayer ID requested)
  • Tax year
  • Notice number (CP20) and any reference ID shown
  • A bullet list of the documents you’re attaching
  • One sentence: “These documents support the item(s) listed in my CP20 notice.”

Takeaway: A simple cover letter increases the chance your response gets processed correctly.

Step 4: Send copies (and keep your own “proof pack”)

Make a complete copy of everything you send. If you mail it, use tracking. If you fax it, save the confirmation page.

Takeaway: If there’s ever a dispute later, your “proof pack” is your safety net.

Step 5: Follow up if you don’t hear back

If the IRS doesn’t respond for a while, call the number on the notice. Be ready with:

  • Tax year
  • Notice type (CP20)
  • Date you sent your documents
  • Tracking number or fax confirmation

Takeaway: Don’t assume “no news” means it’s handled—verify.

Will the IRS hold your refund because of a CP20?

Often, yes—at least the portion connected to the questioned item. The IRS may hold the refund until they review what you send. Once they review your documents, the examiner typically does one of three things:

  1. Accepts your return as filed (and releases the held amount)
  2. Requests more information
  3. Proposes changes (which can reduce your refund or create a balance due)

If your situation turns into a balance due later, this page may help you understand the bigger “balance due letter” chain: IRS Balance Due Letters Explained

Takeaway: A CP20 is commonly tied to refund verification. Your response determines what happens next.

Common mistakes that make CP20 problems worse

  • Missing the deadline (even if your documents are perfect)
  • Sending originals and losing them forever
  • Sending a pile of documents with no explanation
  • Not putting your name/ID on every page (especially if faxing)
  • Ignoring the notice because “I filed honestly”

If you’re tempted to ignore it, don’t. Read this: What Happens If You Ignore an IRS Letter?

Takeaway: Most CP20 damage comes from delay, not from the original issue.

When you should consider getting help

You can absolutely respond to many CP20 notices yourself. But consider professional help if:

  • You don’t understand what item the IRS is questioning
  • The IRS is questioning a large amount of money
  • Your documents are incomplete or hard to get
  • You suspect identity theft or a return filed in your name
  • You get a follow-up proposing major changes

A common “middle ground” is hiring an enrolled agent (EA) or CPA for one hour to help you build a clean response packet.

Takeaway: If the amount is large or the issue is confusing, getting help early can save you time and stress.

How CP20 is different from CP2000

People mix these up all the time.

  • CP20: often an audit-by-mail initial contact asking you to prove you qualify for a questioned item (commonly tied to an overpayment/refund).
  • CP2000: usually a proposed change based on a mismatch between your return and information the IRS received (W-2s, 1099s, etc.).

If you’re actually dealing with a CP2000, use your specific guide here: CP2000 Notice Explained

Takeaway: CP20 is typically “show proof.” CP2000 is typically “here’s our proposed change.”

Simple “CP20 response checklist” you can follow

  • ✅ Read the CP20 and identify the exact questioned item(s)
  • ✅ Gather documents that directly prove eligibility
  • ✅ Write a short cover letter and list your attachments
  • ✅ Copy everything for your records
  • ✅ Send using the method in the notice (mail/fax) and keep proof
  • ✅ Follow up if you don’t get a response

Takeaway: If you do the basics cleanly, you’re already ahead of most people.

FAQ: CP20 Notice Questions People Ask

How long do I have to respond to a CP20 notice?

The deadline is printed on your notice. It’s not the same for everyone. The safest move is to act quickly and aim to send your response well before the due date. If you truly can’t meet the deadline, call the number on the notice and ask what options you have.

Can I respond to a CP20 online?

Some IRS notices allow online upload or digital response options, but many CP20 situations still rely on mail or fax as listed on the notice. Follow the instructions on your letter exactly—don’t assume another method will work.

What happens if I don’t respond to a CP20?

If you don’t respond, the IRS can treat the questioned item as not allowed. That can reduce your refund, delay payment, or even create a balance due. Even if you believe you’re right, silence usually hurts you here.

Does CP20 mean the IRS thinks I committed fraud?

Not automatically. Most CP20 notices are verification requests. The IRS is basically saying, “Prove you qualify.” If you can document your claim, you’re in a strong position.

Will I get my refund after I respond?

If your documentation clearly supports the questioned item, the examiner may accept the return as filed and release the held portion of the overpayment/refund. If they need more proof, they may request more information, or they may propose changes.

Sources (for accuracy)

This page is based on publicly available IRS/TAS guidance about the CP20 series and correspondence audits. For deeper reading, you can look up “Notice CP20 series” on the Taxpayer Advocate Service site and “Understanding your IRS Notice or Letter” on IRS.gov.

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