IRS Tax Audit Guide: What to Expect and How to Prepare (2026)
By Wealthvieu · Updated
An IRS audit is a review of your tax return to verify the information is accurate. While the word “audit” can be stressful, understanding the process and your rights can make it much more manageable.
Table of Contents
Audit Rates by Income Level
Income Level
Approximate Audit Rate
1 in X Returns
Under $25,000 (with EITC)
0.8-1.0%
1 in 100-125
Under $25,000 (without EITC)
0.2%
1 in 500
$25,000 - $99,999
0.15%
1 in 667
$100,000 - $199,999
0.2%
1 in 500
$200,000 - $499,999
0.4%
1 in 250
$500,000 - $999,999
0.8%
1 in 125
$1,000,000 - $4,999,999
1.2%
1 in 83
$5,000,000 - $9,999,999
2.0%
1 in 50
$10,000,000+
3.0%+
1 in 33
Rates are increasing for $400,000+ earners due to Inflation Reduction Act funding.
Types of IRS Audits
Type
Description
Severity
Frequency
Correspondence audit
Handled entirely by mail; IRS requests specific documents
Lowest
~75% of audits
Office audit
You visit an IRS office with requested documents
Medium
~15% of audits
Field audit
IRS agent visits your home or business
Highest
~10% of audits
What Each Type Involves
Feature
Correspondence
Office
Field
Duration
2-6 months
1 day + follow-up
Days to months
Issues examined
1-2 specific items
Multiple items
Comprehensive review
Documents needed
Specific items listed in letter
Broader documentation
Everything related to return
Representation
Can handle yourself
Tax pro recommended
Tax pro strongly recommended
Typical issues
EITC, missing income, specific deductions
Itemized deductions, business expenses
Complex business, high-net-worth
Common Audit Triggers (Red Flags)
High-Risk Items
Red Flag
Why It Triggers Scrutiny
Risk Level
Income discrepancy
Your return doesn’t match W-2s, 1099s, K-1s the IRS received
Very high
High deductions relative to income
Charitable donations > 50% of income, business expenses > 50% of revenue
High
Home office deduction
Historically scrutinized, especially large claims
Medium-high
Cash-intensive business
Tips, restaurants, retail—harder to verify income
High
Large charitable donations
Especially non-cash, without proper documentation
Medium-high
Early EITC claims with errors
IRS heavily audits EITC for compliance
High
Claiming 100% business use of vehicle
Nearly impossible to justify zero personal use
Medium
Cryptocurrency transactions
IRS is increasing enforcement on unreported crypto
Growing
Offshore accounts or income
FBAR and FATCA reporting requirements
Very high
Round numbers on deductions
$5,000, $10,000 (looks estimated, not actual)
Low-medium
DIF Score
Factor
Details
What is it
Discriminant Information Function—IRS’s statistical scoring system
How it works
Compares your return to similar returns (income, occupation, region)
High score =
Greater deviation from norms, higher audit probability
You can’t see it
The DIF score is confidential
IRS Audit Process Timeline
Step
When
What Happens
1. Selection
Anytime within statute of limitations
Return flagged by DIF score, matching program, or random selection
2. Notification
You receive a letter
IRS sends notice by mail (never by email or phone first)
3. Response deadline
Usually 30 days from notice
You must respond or request an extension
4. Document submission
Within deadline
Send only what’s requested, keep copies of everything
5. IRS review
2-12 weeks
Agent reviews your documents
6. Proposed changes
If discrepancies found
IRS sends a report with proposed adjustments
7. Agreement or appeal
30 days to respond
Agree and pay, or appeal the findings
8. Resolution
Varies
Case closed with no change, agreed changes, or appeals process
Statute of Limitations
Situation
IRS Can Audit Within
Standard return
3 years from filing date
Understated income by 25%+
6 years
Fraudulent return
No limit
No return filed
No limit
Filed early (before April 15)
3 years from April 15 (not filing date)
Filed extension, filed October 1
3 years from October 1
How to Prepare for an Audit
Documents to Gather
Category
Documents
Income
W-2s, 1099s, K-1s, bank statements, brokerage statements
Deductions
Receipts, canceled checks, credit card statements
Business expenses
Mileage logs, travel receipts, client lists, business purpose notes