Understanding IRS Letter 531

08.20.2025

When the IRS completes an audit and proposes changes to a taxpayer’s return, it often issues IRS Letter 531. This document, formally titled “Notice of Proposed Adjustment,” signifies a turning point in the audit process. While not a statutory notice of deficiency, it is a crucial step that can lead directly to further tax liabilities and legal consequences if ignored. Understanding the content and implications of this letter is essential for taxpayers and their advisors to take timely, appropriate action.

What Is IRS Letter 531?

IRS Letter 531 is issued when a taxpayer does not agree with the proposed changes detailed in IRS Form 4549 (Income Tax Examination Changes). It is the IRS’s final proposed finding at the administrative level and serves as a precursor to the Statutory Notice of Deficiency—commonly known as the “90-day letter” issued under Internal Revenue Code (IRC) § 6212.

While not itself a statutory notice, Letter 531 is the taxpayer’s last chance to resolve the dispute within the IRS, particularly through the IRS Independent Office of Appeals, without triggering litigation or enforced collection.

What Does Letter 531 Include?

Typically, Letter 531 contains:

    • A clear breakdown of each proposed adjustment to the return;
    • Calculations of increased tax liabilities, penalties, and interest;
    • Enclosures such as Form 4549 and related examination reports;
    • Instructions for how and when to respond—usually within 30 calendar days.

Carefully reviewing the enclosures is critical, as they form the basis for whether the taxpayer should accept or dispute the proposed adjustments.

Response Options

Upon receipt of Letter 531, the taxpayer must promptly choose among the following options:

1. Accept the Adjustments: Agree to the IRS’s proposed changes by signing and returning the agreement forms. The taxpayer can either pay the amount owed or request an installment plan.

2. Informal Resolution: Contact the revenue agent or group manager to discuss the issues or submit additional documentation. This can sometimes resolve disputes without the need for a formal protest.

3. File a Formal Protest: Submit a written protest requesting an Appeals conference. The protest must comply with IRS guidelines, as described in IRS Publication 5, and be submitted within the response window. Failure to do so typically results in the issuance of a statutory notice and loss of certain appeal rights.

Why This Notice Matters

IRS Letter 531 is not merely a procedural formality—it is a legal inflection point. Failing to respond within the specified timeframe may result in:

    • Loss of administrative appeal rights;
    • Immediate issuance of a Statutory Notice of Deficiency;
    • Accrual of additional penalties and interest;
    • Limited future options to contest the tax liability other than through litigation.

Taxpayers should treat this letter with the gravity it warrants. Ignoring it is not an option.

We Can Help!

IRS Letter 531 is a critical document in post-audit tax procedure. It offers taxpayers one final opportunity to challenge the IRS’s proposed changes before the matter escalates. At JH Tax Law, we can help craft a timely, strategic, and informed response to prevent unnecessary tax burdens and safeguard future options.

Contact our office for a confidential consultation today.