Identify what the IRS is asserting before deciding how to respond.
Record the CP or LTR number, tax period, date, proposed or assessed amount, and requested action. Compare the notice with the filed return and relevant records. Keep the notice, supporting documents and evidence of any response.
A notice can concern a proposed adjustment, an assessed balance, identity verification or missing information. The response method and rights depend on the notice. Use its instructions and actual deadline; a general educational page cannot determine the deadline for an unseen notice.
Work through an example
Illustration: if a notice says an extension was missing, the research file might include the extension, acceptance evidence, return transcript and the notice itself. Whether relief is available depends on the actual tax period, penalty and facts.
Return to the sources
Understand an IRS notice or letter
Find the CP or LTR number, identify the tax period and preserve any response deadline.
Administrative penalty relief
Check the current relief program, qualifying penalties, compliance history and affected tax periods.
First edition: November 15, 2026. Educational scope and current links reviewed for this release. Source text and effective dates control.