Few things cause more anxiety than finding a letter from the IRS in your mailbox. But not every IRS letter means you’re being audited — some are notices of discrepancy, while others are formal audit determinations.
Each IRS letter or form has a specific purpose, and knowing how to interpret them can make all the difference between a simple correction and a costly tax problem. This guide breaks down the most common IRS audit-related letters — including CP2000, CP3219A, and others — and explains what to do when you receive one.
For reference, you can verify any IRS notice or letter type at the IRS “Understanding Your Notice or Letter” page.
CP2000 Notice — Underreported Income
A CP2000 is one of the most common IRS letters sent to taxpayers. It means the IRS found a discrepancy between what you reported and what third parties reported (like employers, banks, or brokerage firms).
🔍 What it means?
- The IRS believes you underreported income or made an error.
- The notice proposes changes to your return — not an immediate bill.
📘 Learn more: IRS CP2000 Notice — Underreported Income.
CP3219A Notice — Notice of Deficiency
An IRS CP3219A Notice, also known as a Statutory Notice of Deficiency, is a formal letter the IRS sends when they propose a change to your tax return that increases your tax liability, and you have not responded to earlier correspondence (typically a CP2000 notice).
🔍 What it means?
- The IRS believes you underreported income or made an error on your tax return.
- They have calculated additional tax, penalties, and interest based on information from third parties (e.g., W-2s, 1099s, brokerage statements).
- This notice is the final step before the IRS can assess the tax — it gives you a legal right to challenge the proposed changes in Tax Court.
⚠️ Important Notes
- Do not ignore this notice. After 90 days, the IRS will automatically assess the tax and begin collection actions (e.g., notices of balance due, liens, levies).
- If you disagree but missed the 90-day window, you lose your right to go to Tax Court without first paying the tax and filing a claim for refund.
- You can request IRS account transcripts to compare the information they used with your return.
📘 Learn more: IRS CP3219A Notice — Statutory Notice of Deficiency.
Letter 566 — Examination Notice
IRS Letter 566 is a notice of an audit (examination). It means the IRS has selected your individual or business tax return for review and wants to verify specific items before determining whether any changes are needed.
🔍What it means?
- The IRS has selected your return for audit.
- The letter lists specific items under review (e.g., deductions, credits). It lists the documents or information the IRS needs to verify what you reported.
⚠️ Important Notes
- Respond promptly and provide supporting documentation.
- Keep copies of everything you send.
- If you disagree with the results of the audit, you have appeal rights through the IRS Office of Appeals.
- If the issue involves complex tax positions or potential penalties, it’s often worth having a tax attorney or CPA represent you — especially since correspondence audits can escalate.
📘 Learn more: IRS Publication 556 — Examination of Returns.
Letter 2205-A / 2205-B — Notice of Audit Contact
IRS Letters 2205-A and 2205-B are initial audit contact letters — they notify you that the IRS has selected your tax return for examination (audit) and that an IRS revenue agent will be in touch to begin the process.
🔍 What it means?
- You are being contacted for an audit.
- The IRS will specify which years and issues are being examined.
- The letter may ask you to contact a Revenue Agent or Tax Compliance Officer to schedule the audit and discuss records to be reviewed.
⚠️ Important Notes
If you don’t respond:
- The IRS will move forward without your input;
- Disallow deductions or credits you claimed; and
- Issue a proposed adjustment letter (Letter 4549 or Letter 525).
This can lead to a Notice of Deficiency (CP3219A) — the legal notice that precedes assessment and potential collection.
Letter 525 — Examination Report
IRS Letter 525, titled “General 30-Day Letter”, is a formal notice from the IRS informing you that an audit (examination) of your tax return has been completed and that the IRS proposes changes that would result in additional tax, penalties, and/or interest.
🔍 What it means?
- The IRS has finished reviewing your return (often following a correspondence, office, or field audit).
- They believe you owe additional tax based on their findings.
- The letter includes:
- Form 4549, Income Tax Examination Changes, which details the proposed adjustments,
- An Explanation of Items, showing why each change was made, and
- Instructions for how to agree or disagree with the proposed changes.
⚠️ Important Notes
- Review carefully and note the response deadline.
- You have 30 days to appeal the findings before a Notice of Deficiency is issued.
CP75 and CP75A — Credit Verification
These letters are issued when the IRS wants to verify eligibility for certain credits, such as the Earned Income Tax Credit (EITC) or Child Tax Credit.
🔍 What it means?
- The IRS is asking for documentation (e.g., proof of dependents or income).
- The audit typically focuses on credit qualification rather than income underreporting.
⚠️ Important Notes
- Respond with the requested documents by the listed deadline.
- Failure to respond can lead to disallowance of the credit.
CP14 — Balance Due Notices
This letter indicate you owe the IRS money.
🔍 What it means?
- The CP14 is the first bill the IRS sends when their records show you owe tax, penalties, and/or interest after processing your return.
- It’s not an audit notice — it’s a balance due statement.
⚠️ Important Notes
- Review your account balance at IRS.gov/account.
- Arrange payment or contact the IRS to discuss options before penalties increase.
What to Do if You Receive Any IRS Audit Letter?
- Don’t panic — but don’t ignore it.
The IRS provides clear instructions and response deadlines. - Verify authenticity.
Scammers often impersonate the IRS. The IRS will never contact you by phone, email, or text first. - Gather your documentation.
Maintain copies of all income statements, receipts, and correspondence. - Respond promptly and professionally.
Delays can lead to escalated enforcement. - Seek professional help.
A tax attorney can help you interpret the letter, respond correctly, and prevent further complications.
Need help with a similar issue? Contact our firm today for a consultation.
Each IRS audit letter serves a different purpose — from initial discrepancy notices to final deficiency determinations. Understanding what your letter means helps you respond confidently and protect your rights.
If you’ve received an IRS notice or letter, contact Pelham PLLC today. Our tax attorneys specialize in IRS audits, notices, and appeals — helping individuals and business owners resolve issues quickly and effectively.
You can also review all official IRS letter types at the IRS Notice Directory.
FAQs
What should I do if I receive a CP2000 notice?
Review the proposed changes carefully, compare with your records, and respond by the deadline — either agreeing or providing documentation if you disagree.
Is a CP2000 an audit?
Not technically. It’s a proposed adjustment based on mismatched income data, not a full audit — though it can lead to one if unresolved.
What’s the difference between CP2000 and CP3219A?
A CP2000 proposes a change, while a CP3219A is a Notice of Deficiency, which becomes binding unless you file an appeal or Tax Court petition within 90 days.
How can I confirm if an IRS letter is legitimate?
Use the IRS “Understanding Your Notice or Letter” tool to verify the letter type and authenticity.
What if I miss the deadline to respond?
The IRS may assess the tax automatically and begin collection actions. Contact the IRS or a tax attorney immediately to request reconsideration or appeal.
