When your IRS transcript suddenly shows a freeze code, everything stops—your refund, your processing timeline, and your ability to get meaningful answers from customer service.
In 2026, freeze codes are more common than ever due to enhanced fraud detection, the expansion of OBBB deductions, and more aggressive return integrity checks.

This guide explains every major IRS freeze code, including the often-misunderstood C-Freeze, and how each one affects your refund.

If your refund is stuck, this is the master reference you need.

What Is an IRS Freeze Code?

A freeze code is an internal IRS indicator that tells the system to stop all refund activity until a specific issue is resolved.
Freeze codes:

• Stop refunds from being issued
• Block adjustments
• Prevent updates to account balances
• Trigger notices and identity checks
• Hold the account until manual review is complete

Many taxpayers never receive a direct notice explaining the freeze—your transcript is often the only clue.

The Major IRS Freeze Codes Explained (2026 Edition)

Below is a breakdown of the primary freeze categories, what they mean, what causes them, and how to fix them.

1. The C-Freeze

The Master Administrative Lock That Pauses Your Entire Account

The C-Freeze is a broad administrative freeze often triggered by unprocessed data, conflicting filings, missing documents, or unresolved identity verification issues.
It is one of the most misunderstood IRS freezes.

What C-Freeze Means:
Your refund cannot be released because something in your account needs IRS review before the return can finalize.

Common C-Freeze Causes:

• Unprocessed forms (W-2, amended return, payment mismatches)
• Identity verification pending
• Duplicate return indicators
• Additional information required by CP05/CP75 notices
• Suspicious withholding or refundable credits
• Address or bank mismatch issues

The C-Freeze is not tied to one exact code. Instead, it appears alongside other transaction codes (TC 570, TC 971, TC 420, etc.) that show what triggered the lock.

2. The -A Freeze

Duplicate Return | Amended Return | Identity Verification

The -A Freeze activates whenever the IRS receives more than one return for the same taxpayer or when an amended return (1040-X) is filed.

496 — Duplicate Return Detected

A paid preparer or e-file software may have sent a return twice.
Refund freezes until IRS determines which return is valid.

497 — TC 976/-A

This means a duplicate return was officially logged.
You must verify your identity or confirm which return is correct.

498 — Amended Return -A Freeze

Filing a 1040-X automatically triggers this freeze so the IRS does not pay the wrong refund amount.

499 — 90-Day Resolution Window

If TC 976 posts, the IRS aims to resolve within 90 days.
After that, taxpayers may qualify for Taxpayer Advocate Service (TAS) assistance.

3. The -B Freeze

Refund Statute Expired | Out-of-Time Returns

The -B Freeze triggers when the IRS determines the refund is past the legal deadline.

500 — Refund Statute of Limitations Freeze

Refund claims are generally limited to three years from the due date.
If filed late, credits become non-refundable.

501 — TC 820/-B: Overpayment Sent to Excess Collections

Your refund amount is moved to the Excess Collection File, meaning the IRS cannot legally pay it.

502 — The Two-Year Payment Rule

If withholding or estimated payments happened within two years, some credit may still be refundable.

4. The -W Freeze

Litigation | Bankruptcy | CDP Hearings

This freeze is triggered by legal actions that suspend IRS activity.

503 — Bankruptcy or Litigation Freeze

Refunds stop completely until the court or hearing concludes.

504 — TC 520/-W

The IRS locks refunds and stops collection notices while a case is active.

505 — Hardship Exception via OBR

In rare cases, an Offset Bypass Refund (OBR) can override the freeze for severe hardship.

506 — TC 521 Resolution

Once bankruptcy or litigation ends, TC 521 removes the freeze.

5. The -P Freeze

Refund Fraud Review | RIVO Investigations

This is one of the harshest freeze categories.

507 — High-Risk Fraud Lock

Return Integrity and Verification Operations (RIVO) manually reviews your tax return.

508 — The “777” DLN Pattern

A Document Locator Number containing 7771X means RIVO intercepted your refund.

509 — TC 840/-P

Even manual refund requests are frozen if the IRS suspects incorrect or fraudulent credits.

6. The -R Freeze

Related Account Liability | Business Module Issues

If you own a business or have a related tax account, issues in one account can freeze refunds in another.

Common Causes:

• Payroll tax issues
• Outstanding business liabilities
• Pending adjustments on a related account

This freeze prevents refund release until the related case is resolved.

7. The -S Freeze

Identity Theft | Security Hold | ID Verification Pending

Though not always labeled as “-S”, identity-related freezes fall under this family.

Triggers:

• Letter 5071C issued
• ID.me verification not completed
• Mismatched SSN or filing status
• Suspicious wage or credit activity

Refunds do not move until identity is verified.

8. The -L Freeze

Examination | Audit | EITC/ACTC Review

Many taxpayers mistake an -L freeze for an audit, but it often means examination-level review for refundable credits like EITC and ACTC.

Signs Include:

• CP75 notice
• Documentation requests
• TC 420 (audit/exam started)

An -L Freeze does not release until the IRS confirms eligibility.

9. The -O and -K Freeze Family

Offer in Compromise | Criminal Investigation

Less common, but important:

• -O Freeze: Offer in Compromise pending
• -K Freeze: IRS Criminal Investigation involvement

Refunds are generally prohibited while these freezes are active.

10. The C-Freeze Follow-Up Codes

What Happens After a Freeze Holds the Refund

C-Freezes often appear with these supporting transaction codes:

• TC 570: Refund Hold – Most common freeze indicator
• TC 971: Additional action required (ID verification, review, notice sent)
• TC 420: Examination initiated
• TC 570 + 971: Freeze + Pending verification
• TC 841: Refund reversal due to freeze or rejection
• TC 846: Refund finally released

If TC 846 is missing, the freeze is still active.

How to Resolve Any IRS Freeze Code

1. Ask for the IDRS Control Base

This identifies which IRS unit or employee controls your case.
It bypasses generic call center scripts.

2. Look for Corresponding Notices

C-Freezes never appear alone.
Check for:

• CP05
• CP75
• CP36
• Letter 5071C
• Letter 12C

Each one points to the freeze cause.

3. Submit Required Documents Immediately

Digital uploads through the IRS Online Account now speed resolution dramatically.

4. File Form 8822 for Undeliverable Checks

Returned mail can trigger a freeze.
Fixing your address often resolves the issue.

5. Wait for 45-Day Interest Accrual

If a freeze holds your refund longer than 45 days after filing, the IRS must pay interest.

6. Request TAS Assistance

If you meet hardship criteria or your freeze exceeds normal timeframes, TAS can intervene.

7. Avoid Filing Amendments During Active Freezes

Doing so may extend the freeze unnecessarily.

IRS freeze codes are powerful administrative locks that instantly stop refund issuance.

The major freeze families—C-Freeze, -A, -B, -W, -P, -R, -S, and -L—each signify a specific kind of problem:

• Duplicate return
• Expired refund statute
• Bankruptcy or litigation
• Fraud suspicion
• Related account issues
• Identity verification
• Examination of refundable credits

Understanding your freeze code is the first—and most important—step toward getting your refund released.