Audits, the 30-day letter, appeals and the 90-day letter

An IRS exam ends with a revenue agent's report and a 30-day letter; you can agree (Form 4549), request Appeals (with a written protest if over $25,000 per period), or wait for the 90-day letter (statutory notice of deficiency), after which you have 90 days (150 if abroad) to petition the Tax Court before the IRS can assess.

Updated 2026-09-23 · 4 sources · By the EnrolledAgentKit team
Exam part
Part 3
Representation, Practices and Procedures
IRS domain
Specific Areas of Representation
20 of 85 scored Qs
Tax year tested
2025
2026-27 SEE
Practice questions
11
10 free below

The rules the exam tests

Figures for tax year 2025, the year the 2026-27 SEE tests. Verify against the cited primary source.
RuleWhat it says (2025)Source
Exam typesCorrespondence, office, fieldPub 556
Time and placeIRS sets a reasonable time and placeIRC 7605(a)
One inspection ruleBooks examined once per year unless notice givenIRC 7605(b)
Right to consultInterview suspended on request (except summons)IRC 7521(b)(2)
30-day letterAgree, or request Appeals within 30 daysPub 5
ProtestFormal written protest if > $25,000 per period; small case request otherwisePub 5
90-day letterNotice of deficiency; 90 days (150 abroad) to petition; no assessment meanwhileIRC 6212, 6213
Small tax case<= $50,000 per year; not appealableIRC 7463
Burden of proof shiftCredible evidence + substantiation + cooperationIRC 7491
EA privilegeNoncriminal tax advice onlyIRC 7525
Audit reconsiderationAfter assessment with new information; not after Tax Court decision or closing agreementIRS
Worked example

Facts: A field exam proposes a $40,000 deficiency for 2023. The client disagrees with $30,000 of it.

Path: Sign a partial agreement for the $10,000 conceded issue (stops interest on that part), and within 30 days file a formal written protest (over $25,000) requesting Appeals. If Appeals cannot settle, the IRS issues a 90-day letter and the client has 90 days to petition the Tax Court; with $30,000 in dispute she may elect small tax case (S case) procedures, whose decisions cannot be appealed.

Exam traps

  • The Tax Court deadline is 90 days (150 abroad) from the notice of deficiency, and it cannot be extended.
  • Protest threshold is $25,000 per period; S-case limit is $50,000 per year.
  • EAs cannot argue in Tax Court unless admitted.
  • Audit reconsideration is unavailable after a Tax Court decision.

Audits, the 30-day letter, appeals and the 90-day letter: 10 free practice questions

Audits, the 30-day letter, appeals and the 90-day letter practice questions

What is a 90-day letter?

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Frequently asked questions

What is a 90-day letter?

A statutory notice of deficiency. You have 90 days (150 if outside the U.S.) to petition the Tax Court before the IRS can assess.

Do I need a written protest to go to Appeals?

Yes, a formal written protest if more than $25,000 is at issue for any period; a small case request otherwise.

Sources

  1. IRS Publication 556 - Examination of Returns, Appeal Rights, and Claims for Refund (accessed 2026-09-23)
  2. IRS Publication 5 - Your Appeal Rights and How to Prepare a Protest (accessed 2026-09-23)
  3. IRS - SEE Part 3 content specifications (Representation, Practices and Procedures) (accessed 2026-09-23)
  4. IRS - Enrolled agents: Frequently asked questions (accessed 2026-09-23)