2.3 IRS Notices and Deadlines

A tax attorney’s first task is to determine whether the client has any imminent legal deadlines. The quickest way to find out this information is by reviewing recent IRS notices received by the client. IRS notices are famously opaque and difficult to read, and a client may not understand what they say. You should ask the client for all and any IRS notices in the client’s possession. Each IRS notice can be identified by its CP number. This number should be in the upper right of the first page of the notice. You can find information on how to understand and respond to many IRS notices at “Understanding Your IRS Notice or Letter”.1 Most notices will apply to only at one tax year, which is also listed in the upper right of the first page.

Common IRS notices are:

• Notice of Proposed Changes to Tax Return, CP-2000 Notice (30 days to reply)
• Penalty and Interest Notices on Liability Already Assessed (30 days to reply)
• Notice of Examination or Audit Notice

These deadlines can generally be extended. Call the IRS for an extension to reply to a CP-2000 notice. (IRS phone numbers may be staffed until about 8 p.m. on weekdays). 

Other notices that have deadlines to appeal or file suit should be strictly complied with. These include:

• Examination Report, Form 4549 or 886-A (30 days to reply or appeal)
• The 30-day letter notifying taxpayer of the right to appeal (30 days to appeal by protest letter)2
• Notice of Tax Deficiency or “the 90-day letter” (deadline to file petition in the Tax Court given in the Notice)
• Notice of Determination on Collection Due Process Appeal (30 days to file petition with Tax Court)
• Notice and Demand for Payment, CP-14
• Notice of Federal Tax Lien (30 days to appeal by Form 12153)
• Final Notice Before Levy on Social Security Benefits, CP-91/298 (30 days to reply)
• Final Notice of Intent to Levy, CP-90/CP-297 (30 days to appeal by Form 12153; if bank account levy, 21 days before bank remits funds to IRS)
• Notice of Seizure (10 days to appeal by Form 9423; about 60 days to sale)
• Denial of Installment Agreement (30 days to appeal by Form 9423)
• Termination of Installment Agreement, CP-523 (30 days to appeal by Form 9423)

• 1Understanding Your IRS Notice or Letter, Internal Revenue Serv., (last updated Dec. 1, 2022).
• 2Note that a taxpayer should not sign the Form 870 included with these notices since it will waive right to petition the Tax Court.