IRS Freeze Codes — Easy Study Guide

Based on your uploaded IRS Internal Revenue Manual (IRM 21.5.6), revised August 12, 2026, with an effective date of October 1, 2026.

Your PDF is 206 pages long, so you do not need to memorize every procedure word for word. The best way to study it quickly is to learn what each freeze code means, what it usually affects, and what you should remember when researching an account.

21.5.6 Freeze Codes _ Internal Revenue Service.pdf

1. First, understand what a freeze code is

An IRS freeze code is an indicator on a taxpayer's account that tells an IRS employee that something needs attention or that certain account actions are restricted.

A freeze may affect:

• Refunds: Money the IRS owes the taxpayer.
• Offsets: Moving credits to pay another tax liability.
• Balance-due notices: Notices requesting payment.
• Account adjustments: Changes to tax, credits, penalties, or interest.

The manual groups freeze conditions into three broad types:

1. Conditions that hold refunds and restrict offsets but do not stop balance-due notices.

2. Conditions that stop certain notices, refunds, and offsets.

3. Indicators that identify an account issue but do not necessarily freeze the account.

   21.5.6 Freeze Codes _ Internal Revenue Service.pdf

Most important rule: Research the account in IDRS before taking action. Do not assume that every freeze should be manually released.

2. The freeze codes — simplified meanings

The IRS uses similar letters with different signs. The sign matters: A- and -A are different freeze codes.

A–E: Returns, credits, refunds, and examination

Code	Easy meaning	What to remember
A-	Collection statute issue	A credit exists for offset, and the earliest CSED on a balance-due module has expired.
-A	Duplicate or amended return	A duplicate, subsequent, or certain amended returns may trigger a refund hold.
B-	Payment or account-credit issue	A payment or offset creates a situation requiring account correction.
-B	Refund time limit expired	Check the Refund Statute Expiration Date (RSED) and whether the credit is refundable.
C-	Refund hold or offset problem	May hold a refund or indicate an offset-processing problem.
-C	Combat-zone indicator	Identifies a qualifying combat-zone account.
D-	Estimated-credit discrepancy	The taxpayer claims more estimated tax credits than are available, among other listed conditions.
-D	Refund statute issue	An expired RSED or qualifying account adjustment can trigger this freeze.
E-	Original return missing	Certain duplicate or amended return activity occurs without an original return posting.
-E	Credit discrepancy or refund screening	May involve an employment-tax deposit discrepancy or a restricted refund. Specific procedures depend on the reason code and account indicators.

F–J: Payments, math errors, interest, and credits

Code	Easy meaning	What to remember
F-	Frivolous return	Associated with the Frivolous Return Program.
-F	Advance payment	A payment is made toward a determined deficiency before assessment.
G-	Restricted failure-to-pay penalty	Penalty or interest-related restrictions need review.
-G	Math error	The IRS changed or corrected the return during processing.
H-	Credit can pay another account	An individual overpayment may be applied toward a business-tax liability; another H- situation involves a designated penalty payment.
-H	Business-account credit balance	A payment posted to a period with no filing requirement.
I-	Invalid or unprocessable return information	May involve an invalid return segment or missing requested information, with credit interest restricted.
-I	Debit interest restriction	Manual interest computation may be required.
J-	Excess credits	The account has credits that need to be identified or reconciled.
-J	Disputed math error	A taxpayer's unsubstantiated math-error protest results in a review process.

K–O: Erroneous credits, examination, notices, and disasters

Code	Easy meaning	What to remember
K-	Erroneous or partly refundable credit	The account has a credit balance, but the credit is not entirely refundable.
-K	Adjustment hold	Certain examination or data-processing adjustments hold credits from refund or offset.
L-	Heavy Highway Vehicle Use Tax credit	Certain Form 2290 credit balances are held to prevent erroneous refunds.
-L	Open examination	Examination involvement must be researched before adjusting the account. The account is not automatically frozen.
M-	Account transfer	Associated with a transfer transaction.
-M	Maritime industry filer	Identifies a maritime industry filer.
N-	Notice status	The module is in notice status until specified conditions are met.
-N	Sustained penalty appeal	Associated with penalties previously sustained by the Independent Office of Appeals.
O-	Account re-established	The module is re-established or reactivated on the Master File.
-O	Disaster indicator	Provides qualifying disaster-related penalty and interest relief; it does not itself prevent refunds.

P–T: Refund repayments, discrepancies, collections, and legal restrictions

Code	Easy meaning	What to remember
P-	Refund repayment or cancellation	May involve a returned refund, repayment, or rejected direct deposit.
-P	Estate/trust beneficiary offset	Applies to certain Form 1041 beneficiary-offset situations.
Q-	Federal tax deposit discrepancy	Certain business returns have excess or unclaimed federal tax deposit credits.
-Q	Unallowable refund	Holds the unallowable portion of a claimed refund.
R-	Multiple payment transactions	May involve multiple payments or a payment posted to the wrong account.
-R	Pending tax liability or refund review	A pending liability or refund-screening issue can prevent a refund from releasing.
S-	Undelivered refund check	The refund check was returned or the account lacks an address needed for the refund.
-S	Disaster relief indicator	Provides certain disaster-related penalty and interest relief, but not the full compliance relief of -O.
T-	Collection assignment	Indicates a Tax Delinquent Account (TDA) collection status; it is not itself a freeze.
-T	Special indicator	Consult the applicable IRM and account research; the PDF does not provide a general action to take based on this indicator alone.

U–Z and the new 1- code

Code	Easy meaning	What to remember
U-	Active installment agreement	Certain system-generated balance-due notices are suppressed while the agreement is active.
-U	Erroneous refund	Holds refunds and offsets until the erroneous refund is repaid or the applicable statutory period expires.
V-	Outstanding liability	Indicates an outstanding liability on another account or with another agency.
-V	Bankruptcy	Protects against prohibited collection actions on covered pre-bankruptcy liabilities.
W-	Claim pending	A refund claim or payment-tracer issue is pending resolution.
-W	Litigation	Indicates a litigation-related restriction, including certain bankruptcy-related cases.
X-	Large credit balance	Prevents certain automatic refunds or offsets when a credit reaches the applicable threshold.
-X	Manual refund	A manual refund was issued; the return or other account posting may later release the freeze.
Y-	Data-processing or audit adjustment	Associated with certain adjustments using hold codes.
-Y	Offer in Compromise (OIC)	An offer is pending or accepted. Do not manually release this freeze.
Z-	Specialized indicator	The PDF's description is restricted; use the applicable official IRM procedures.
-Z	Specialized indicator	The PDF's description is restricted; use the applicable official IRM procedures.
1-	Missing or invalid bank details	A qualifying individual return has a refund, but bank information is missing or invalid. The taxpayer may be asked to update it or request a waiver.

Source: Uploaded IRM 21.5.6, Section 21.5.6.4, Freeze Code Procedures. These are simplified descriptions, not complete processing instructions. Some code meanings depend on transaction codes, reason codes, account type, and other indicators.

21.5.6 Freeze Codes _ Internal Revenue Service.pdf

3. The easiest way to memorize them

Instead of memorizing all the letters randomly, learn these high-value associations first.

Returns and math errors

• -A = Amended or duplicate return
• -G = Math error
• E- = Original return missing
• -L = Examination involvement

Credits and payments

• K- = Erroneous credit
• Q- = Federal tax deposit discrepancy
• R- = Multiple payment transactions
• B- = Payment or account-credit issue

Refunds and time limits

• -B = Refund statute expired
• C- = Refund hold or offset problem
• P- = Refund repayment or cancellation
• -U = Erroneous refund
• -X = Manual refund

Special situations

• -O / -S = Disaster-related indicators
• -V = Bankruptcy
• -Y = Offer in Compromise
• U- = Active installment agreement
• S- = Undelivered refund check

4. The most important difference: the letter versus the sign

Never assume a letter and its reversed version mean the same thing.

Compare	Remember
-A vs. A-	Amended/duplicate return vs. collection statute issue
-B vs. B-	Refund time limit vs. payment/account-credit issue
-G vs. G-	Math error vs. restricted failure-to-pay penalty
-O vs. O-	Disaster relief vs. account re-establishment
-U vs. U-	Erroneous refund vs. installment agreement
-Y vs. Y-	Offer in Compromise vs. data-processing/audit adjustment

5. What to do when you see a freeze code

Use this simple workflow when studying a case:

1. Identify the exact freeze code

Include the position of the hyphen.

2. Research the account in IDRS

Review transaction codes, account history, and other freeze indicators.

3. Find the reason for the freeze

Determine what caused it and what actions are restricted.

4. Follow the specific IRM procedure

Resolve, refer, or leave the freeze in place as directed.

The manual specifically warns employees not to act on a freeze before completing IDRS research. Multiple freeze conditions can exist on the same account, so resolving one does not necessarily resolve the others.

21.5.6 Freeze Codes _ Internal Revenue Service.pdf

6. Quick practice quiz

Test yourself before reviewing the table again. Select an answer to each question.

1. Which code is associated with a math error?

-A

-G

-B

2. Which code indicates an Offer in Compromise?

Y-

-Y

-V

3. Which code indicates an undelivered refund check?

S-

-S

P-

4. Which code is associated with an erroneous refund?

U-

-U

-X

5. Which code indicates examination involvement?

-L

L-

-N

6. What should you do before taking action on a freeze?

Release it immediately

Research the account in IDRS

Ignore other freeze codes

Check answers

My recommendation: Spend 5 minutes learning the core meanings and the sign differences, then take the quiz. After that, study the detailed IRM procedures for the codes you encounter most often. This guide is a memory aid; always use the official manual for actual account work