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IRS NOTICE Letter 566

Audit Initiation Letter

Quick answer

Notification that your return is under examination. Document requests are usually included.

What is an IRS Letter 566 notice?

Notification that your return is under examination. Document requests are usually included.

A Letter 566 is a review of specific items on a return. It is not, by itself, a finding that anything was done wrong. For the IRS's own overview of notices and letters, see the official Understanding Your IRS Notice or Letter page on IRS.gov.

What does a Letter 566 look like?

A genuine Letter 566 is a paper notice with the notice number "Letter 566" printed in the upper-right corner, the tax year it concerns, a short plain summary of the issue, the amount involved (if any), and a section explaining how and by when to respond.

When reading a Letter 566, it helps to locate four things: the notice code (so you know which notice it is), the tax year it applies to, any dollar amount, and the response or payment date. Those four details tell you most of what the notice is about.

Why did the IRS send a Letter 566?

Return was selected for audit, often via the IRS DIF score or third-party data matching.

Is a Letter 566 real, or a scam?

Scam letters sometimes imitate IRS notices. A real Letter 566 arrives by mail, shows an official notice number, and never demands payment by gift card, wire, or cryptocurrency, and never threatens immediate arrest.

How time-sensitive is a Letter 566?

The response date for a Letter 566 is the date printed on the notice itself. Always go by that printed date and confirm it against your own copy — do not rely on a general estimate.

What happens if you don't respond to a Letter 566?

Ignoring an IRS notice generally makes the situation harder to resolve — interest and penalties can continue to build, and the IRS can send further notices or take further action. It is almost always better to review the notice and respond by the printed date.

General next steps

In general, these are some of the steps people take for this type of notice — not advice about your specific situation.

When to get help

Many notices can be reviewed and handled by reading them carefully. For serious or confusing ones, or if you are unsure, contact the IRS at the number printed on the notice, or a licensed tax professional — a CPA, an Enrolled Agent, or a tax attorney.

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Related IRS notices

CP3219A
Statutory Notice of Deficiency
Letter 525
30-Day Examination Report
CP75
EITC Audit — Documentation Requested
CP05A
Refund Review — Documents Required

Frequently asked questions about the Letter 566

What is an IRS Letter 566 notice?

Notification that your return is under examination. Document requests are usually included.

Why did I receive a Letter 566?

Return was selected for audit, often via the IRS DIF score or third-party data matching.

What does a Letter 566 look like?

A genuine Letter 566 is a paper notice from the IRS with the notice number "Letter 566" printed in the upper-right corner, the tax year it concerns, a short summary of the issue, and a section explaining how and by when to respond.

How time-sensitive is a Letter 566?

The response date for a Letter 566 is the date printed on the notice itself. Always go by that printed date and confirm it against your own copy — do not rely on a general estimate.

Is a Letter 566 a scam?

Some scam letters imitate IRS notices. A real Letter 566 arrives by mail, shows an official notice number, and never demands payment by gift card, wire transfer, or cryptocurrency, and never threatens immediate arrest. When in doubt, verify by calling the IRS at 1-800-829-1040.

What happens if I ignore a Letter 566?

Ignoring an IRS notice generally makes things harder to resolve — interest and penalties can continue to build and the IRS can send further notices or take further action. It is almost always better to review it and respond by the printed date.

Do I need a tax professional for a Letter 566?

Many notices can be reviewed and handled by reading them carefully and responding as instructed. For serious or confusing notices, or if you are unsure, a CPA, Enrolled Agent, or tax attorney can help. This is educational information, not advice about your situation.

How do I know a Letter 566 is really from the IRS?

The IRS initiates contact about a notice by mail, not by unsolicited email, text, or phone. A real Letter 566 has an official notice number and references a specific tax year. You can confirm any notice by calling the IRS directly using the number on IRS.gov.

Tax Panic provides educational information only. This is not tax or legal advice, does not interpret your legal rights, and does not tell you what to do about your specific situation. Not affiliated with the IRS. For your situation, contact the IRS at the number on your notice or a licensed tax professional.