IRS notices glossary and response guide
IRS notices can feel urgent, but most are informational or request additional details. This guide explains common IRS letter types, how to verify your account, and which TaxGuide Pro tools help you decode notices, estimate penalties, and draft responses.
Common IRS notice types
- CP2000: mismatch between IRS records and your return.
- CP14: balance due notice with penalties or interest.
- LTR letters: information or documentation requests.
What to do first
- Confirm the notice number and tax year.
- Compare IRS figures to your return and supporting documents.
- Respond by the deadline if action is required.
When to seek help
If the notice involves audits or large balances, consider a tax professional.
- Large penalties or interest that you cannot resolve.
- Requests for documentation you cannot locate.
Put this tax guide into practice
Identify the tax year, filing status, income type, and household or business facts that apply before comparing options. Keep the source documents behind each number and use the linked calculator for a repeatable estimate. Changing one assumption at a time makes it easier to see which rule drives the result.
Review the calculator's assumptions, caveats, update date, and primary source links before acting. A guide can explain the planning framework, but official forms and instructions control a filed return. Seek qualified advice for notices, amended returns, multiple jurisdictions, business entities, or material transactions.
Save the assumptions used with the estimate and revisit them after an official annual adjustment or a change in income, residency, household, employment, or investment plans. Consistent inputs make comparisons meaningful.
Related calculators
IRS letter/notice decoder
Identify IRS notice types and summary actions.
CP2000 response draft builder
Create a response draft for CP2000 notices.
Penalty + interest estimator
Estimate penalty and interest exposure.
Payment plan fit wizard
Check IRS payment plan options.
Transcript terms translator
Decode IRS transcript terms and codes.
FAQ
Should I ignore an IRS notice if I think it is wrong?
No. Always respond by the deadline with documentation or clarification.
How long do I have to respond to a CP2000 notice?
Most CP2000 notices require a response within the timeframe listed on the letter.
Updated 2026-01-20. TaxGuide Pro provides educational tax guidance, not legal advice.