A Notice of Deficiency is a formal letter from the IRS informing a taxpayer of a tax deficiency and advising them of their appeal rights with the United States Tax Court. It is required by law and is sent by registered or certified mail to the taxpayer's last known address. Although a Notice of Deficiency can be issued when no tax return has You'll Receive a Notice of Deficiency if You Don't Reply to IRS or Appeal Your Case: Referred to as a "90-day letter" by tax practitioners, the IRS mails you a Notice of Deficiency requesting you to respond to the notice within 90 days (the IRS is required to list the actual deadline on page of of the notice). The IRS requires you to respond to What You Should Do After Receiving an IRS Notice of Deficiency 4. Understanding the IRS Collection Process 5. Complying With the Notice 6. Considering an Appeal to IRS Notice of Deficiency Receiving letters or notices from the IRS is often a mixed bag. IRS Form 5564 is included when the federal tax agency sends the IRS Notice CP3219A. The form is known as a Notice of Deficiency-Waiver, and it is used when the taxpayer has no objection to the IRS proposal. If the taxpayer agrees with the IRS proposal, they are required to sign the waiver and mail it to the IRS. Under Sec. 6212 (a) the IRS can issue a statutory notice of deficiency, also known as a 90-day letter, when it determines a deficiency in an income or estate and gift tax liability. A 90-day letter is a formal legal notice, sent by certified or registered mail. Taxpayers have a statutory 90-day window from the date of the notice to either agree Letter 525 - General 30 Day Letter. Letter 531 - Notice of Deficiency. Letter 692 - Request for Consideration of Additional Findings. Letter 915 - Letter to Transmit Examination Report. Letter 950 - 30 Day Letter-Straight Deficiency or Over-Assessment. Letter 1153 - Trust Funds Recovery Penalty Letter. Letter 3016 - IRC Section 6015 Preliminary The Notice of Deficiency IRS Letters 3219 and 531 (also referred to as 90-Day Letters), are a taxpayer's legal notice that the IRS is proposing a deficiency (balance due). This notice or letter may include additional topics that have not yet been covered here. Please check back frequently for updates. Important The IRS notice of deficiency tells you what information was different and lets you know how much tax you owe as a result of the changes. To take a simple example, imagine you reported an income of $20,000 from a W-2 Form from your employer. However, when your employer sent a W-2 to the IRS, that form said your income was actually $25,000. An IRS Notice of Deficiency (Form CP3219A/N) informs the taxpayer that either there has been an increase in the amount of tax due to the IRS or no tax return was received. This judgment is determined after your appeal or 30 days after non-response. If you disagree with the notice, contact the IRS over the phone or send a written explanation supporting your position. You can also contact the third party that reported the information in question (e.g. employer) and ask them to correct it. The IRS will let you know how long you have to contest the notice. A Notice of Deficiency is sometimes referred to as a 90-day letter. The Notice of Deficiency tells you the tax IRS assesses plus the interest and penalties you owe.