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IRS Letter 566:here's whatit means.
Audit or examination. The IRS is examining your return and is asking for documents or proposing changes.
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What is IRS Letter 566?
Audit or examination. The IRS is examining your return and is asking for documents or proposing changes. Respond by the date on the letter.
Updated November 2026. Serving all of California online.
Deadline
Respond by the date on the letter.
If you ignore it
The IRS can finalize changes without your input and assess additional tax.
Similar letters: Letter 525, 2205.
What to do now.
- 1Read exactly which items and years the IRS is examining.
- 2Gather records for those items only, organized and complete.
- 3Have a representative respond and handle the examiner's questions.
General information, not legal advice. The exact deadline is printed on your notice.
Common questions.
Is IRS Letter 566 real or a scam?
Real IRS notices arrive by U.S. mail, not by text, social media, or a surprise phone call demanding payment. To verify, compare it with your IRS online account or call the number listed on IRS.gov, not a number from a suspicious message. We can check it for you.
Can MM.TAX respond to IRS Letter 566 for me?
Yes. Our practice is led by an IRS Enrolled Agent. We file a power of attorney (Form 2848), pull your transcripts, and respond to the IRS for you, online anywhere in California.
What if I can't pay what the IRS says I owe?
You have options: an installment agreement, an Offer in Compromise if you qualify, penalty abatement, or currently-not-collectible status during hardship. The right choice depends on your income, assets, and the amount owed.
IRS notices
Look up another letter.
- CP14Balance due
- CP501Reminder: unpaid balance
- CP504Notice of intent to levy
- LT11Final notice of intent to levy
- CP2000Proposed changes to your return
- CP3219ANotice of deficiency
- Letter 3172Federal tax lien filed
- CP2501Income doesn't match your return
- CP59No record of your tax return
- CP11Changes to your return, balance due
- CP161Business balance due
- LT16Contact us about overdue taxes
- Letter 1153Trust fund recovery penalty proposed
- Form 668-ABank or wage levy
Get started
Let us handle your Letter 566.
Free 30-minute review with a senior advisor. Call the online team or answer a few questions.