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How To Read IRS Transcript Codes

Your IRS account transcript is a wall of three-digit codes. Here's a decoder covering the codes that tell you what the IRS actually did to your account.

You pulled your IRS account transcript hoping for clarity. Instead, you got thirty lines of three-digit codes, dates, and dollar amounts—most with no explanation. TC 290. TC 520 cc 72. TC 971 AC 069. Somewhere in there is the story of what the IRS has actually done to your account.

This is the decoder. Every code below is drawn from IRS Document 6209, the IRS's internal reference. For how to get transcripts, start with the companion: How To Get and Read Your IRS Transcripts. Skim the tables. Stop where a code matches one on your own transcript.

How To Read a Transcript Line

Each line on an account transcript has five parts:

Date—when the transaction posted. Not always the date the event happened.
Transaction Code (TC)—a three-digit processing instruction. Per Document 6209 Section 8A, TCs "identify a transaction being processed and … maintain a history of actions posted to a taxpayer's account on the Master File."
Description—a short IRS phrase; often abbreviated. The code itself is authoritative.
Amount—positive (debit) assesses; negative (credit) abates, pays, or refunds. Zero usually means a system action.
DLN—a 14-digit Document Locator Number. Structure (per Document 6209 Section 4): File Location Code (2) + Tax Class (1) + Document Code (2) + Julian Date (3) + Blocking Series (3) + Serial Number (2) + List Year (1). Most pro se readers can ignore the DLN. It occasionally carries meaning—for example, blocking series 200–299 on a TC 150 indicates an amended return.

Filing and Assessment Codes

These codes establish your tax module and track formal assessments. Two terms you'll see throughout this article:

Tax module — one tax form for one tax period (for example, your 2023 Form 1040). An Account Transcript is organized by module; codes and freezes apply to a specific module, not your entire account.
Freeze — an account-level flag (like —W or —V) that blocks certain automated actions such as levy, refund issuance, or assessment. Freezes come on and off as transactions post.

Code	What It Means
TC 150	Return filed; tax liability assessed. Establishes the tax module.
TC 290	Additional tax assessment (non-exam). Often posts at $0—see callout below.
TC 291	Abatement of prior tax assessment (reverses TC 150, 290, or 300).
TC 300	Additional tax assessment by Examination or Appeals. Formal assessment from an audit or Tax Court deficiency.
TC 301	Abatement by Examination or Appeals (reverses TC 150, 290, or 300).
TC 420	Examination indicator. Audit in progress.
TC 421	Reverse examination indicator. Audit closed.
TC 424	Examination request indicator. Often posts when AUR refers a case to Exam.
TC 425	Reversal of TC 424.
TC 428	Exam/Appeals case transfer between offices.
TC 470	Taxpayer claim pending. Holds notices while a claim is reviewed.
TC 494	Notice of Deficiency issued (the 90-day letter).
TC 495	Closes a TC 494 (or corrects one posted in error).
TC 570	Additional liability pending / credit hold. Freezes refunds and offsets.
TC 977	Amended return posted. The next TC 29X shows whether the IRS agreed.

The TC 290 $0 Trap

A TC 290 at $0 does not mean you owe more tax. TC 290 is the catch-all "additional tax assessed" code, but it only actually changes your tax when it posts with a dollar amount. When it posts at $0, it's a bookkeeping entry—the IRS uses it to release an account freeze, to record that it considered an adjustment request (the DLN's blocking series tells you which: 960–969 = request rejected; 970–979 = request allowed), or to hold the module open during an audit. The NTA's Understanding Tax Account Transcripts blog confirms that TC 290 is routinely "used to release account freezes with zero amounts."

Rule of thumb: if TC 290 posts at $0 and nothing else on the transcript changes your balance, your tax has not changed. Compare the balance before and after—if it's the same, you don't have a new bill.

Penalty and Interest Codes

Penalty and interest codes follow a pattern: even numbers assess, odd numbers abate. TC 166 assesses the failure-to-file penalty; TC 167 abates it. TC 276 assesses failure-to-pay; TC 277 abates. This is a heuristic for the IMF penalty/interest cluster in the 160–299 range and most 7XX credit codes—not a universal law.

Code	Debit / Credit	What It Means
TC 160 / 161	Debit / Credit	Manual FTF penalty—assess / abate.
TC 166 / 167	Debit / Credit	Computer-generated FTF penalty—assess / abate.
TC 170 / 171	Debit / Credit	Estimated tax penalty (manual)—assess / abate.
TC 176 / 177	Debit / Credit	Estimated tax penalty (computer-generated)—assess / abate.
TC 190 / 191	Debit / Credit	Manually assessed interest transferred in—assess / abate.
TC 196	Debit	Computer-generated interest. Posts at first notice, upon assessment of TC 290/300, at TDA/BAL DUE, or when TC 680 posts.
TC 197	Credit	Abatement of assessed interest.
TC 240 / 241	Debit / Credit	Miscellaneous civil penalty—assess / abate. Accuracy-related penalty under IRC § 6662 posts here with a Reference Number.
TC 270 / 271	Debit / Credit	Manual FTP penalty—assess / abate.
TC 276 / 277	Debit / Credit	Computer-generated FTP penalty—assess / abate.
TC 340 / 341	Debit / Credit	Restricted interest—assess / abate. Once TC 340 posts, the computer stops auto-accruing interest on that module.

For how these penalty amounts are calculated, see Understanding Your IRS Balance. To challenge the abatable penalties, see How To Request IRS Penalty Abatement. A TC 290 at $0 with blocking series 960–969 means an abatement request was rejected—worth knowing before you file a second request.

Payment and Credit Codes

Money moving into or out of your account:

Code	What It Means
TC 610	Remittance with return. The payment sent with your 1040.
TC 640	Advance payment of a determined deficiency or AUR proposal (including a § 6603 deposit). Freezes offsets and refunds.
TC 660	Estimated tax payment.
TC 670	Subsequent payment (any payment after the return posted). May carry a Designated Payment Code.
TC 706	Overpayment applied from another tax module (paired with debit TC 826).
TC 766	Refundable credit allowance (EITC-type credits verified on return or from adjustment). Also records TOP offset reversals.
TC 768	Earned Income Credit.
TC 806	Credit for withheld taxes and excess FICA (W-2 / 1099 withholding).
TC 846	Refund of overpayment. The date next to TC 846 is the scheduled refund date.

The 10 years CSED under IRC § 6502 runs from the date of assessment (TC 150 for self-assessed tax; TC 290 or TC 300 for additional assessments). Payments don't extend the CSED. See Understanding IRS Statutes of Limitations.

Collection Action Codes

Collection codes tell you when the IRS is pursuing you, when collection has paused, and when the debt has legally expired. This is the section pro se readers most often need.

Offer in Compromise Codes

Code	What It Means
TC 480	OIC pending. Freezes the module; suspends ASED and CSED.
TC 481	OIC rejected (processable). Releases freeze; extends ASED/CSED.
TC 482	OIC withdrawn/terminated. Releases freeze; extends ASED/CSED.
TC 483	Correction of erroneous TC 480 (offer was not processable). Reverts to normal date.
TC 488	Installment and/or manual billing (module status 14). Documents the billing schedule—not the acceptance code.
TC 780	Master File Account Compromised—the OIC-accepted code.
TC 788	All collateral conditions of the offer completed.

The OIC-accepted sequence is TC 480 → TC 780 → TC 788. TC 480 followed by TC 481 or TC 482 means rejected or withdrawn. See How To Apply for an Offer in Compromise.

TC 520 and Its Closing Codes

TC 520 means "IRS Litigation Instituted"—but the real meaning lives in the two-digit closing code (CC) that follows it. The closing code identifies what kind of litigation, sets the account freeze, and controls whether the CSED is suspended. Source: Document 6209 Section 11, TC 520 Closing Code Chart.

CC	What It Means	Freeze	CSED Suspended?
60–67	Bankruptcy (various chapters)	—V	Yes
70 / 75	Litigation (general)	—W	No
71 / 73	Refund Litigation	—W	No
72	Tax Court Case	—W	No
74	Tax Court Case (alternative variant)	—W	No
76	Collection Due Process—Lien	—W	Yes
77	Collection Due Process—Levy	—W	Yes
78–81	Litigation	—W	Varies
82	Civil Penalty with Appeal Rights	—W	Yes
83–89	Bankruptcy (BAPCPA indicators)	—V	Yes

The codes most relevant to Tax Court and collection disputes:

CC 72—Tax Court Case. The IRS's confirmation that your petition has been filed and a —W litigation freeze is in place. Collection on the deficiency is barred under IRC § 6213(a); the CSED is suspended by operation of IRC § 6503(a). See How IRC 6213 Protects You While Your Tax Court Case Is Pending.
CC 74—Tax Court Case (alternative). Document 6209 also lists CC 74 as "Tax Court Case." Both apply the —W freeze. The distinction is internal to IRS Counsel's case-handling workflow; the primary source does not define it further.
CC 73—Refund Litigation. Not Tax Court. Means a refund suit was filed in district court or the Court of Federal Claims. If you see CC 73 and only filed in Tax Court, something is wrong.
CC 76 and CC 77—CDP hearing requests (lien and levy). CSED suspended. See Collection Due Process Hearings.
CC 81—Litigation. Not bankruptcy. Bankruptcy closing codes are CC 60–67 and CC 83–89 (both —V freeze).

TC 521 reverses TC 520 (case closed). TC 522 marks a TC 520 posted in error—closing codes zeroed out.

TC 530 and Currently Not Collectible

TC 530 means "Currently Not Collectible." A balance is on the books but the IRS has stopped active collection. The closing code tells you why. Source: Document 6209 Section 11; reasons track IRM 5.16.1.

CC	Reason
03	Unable to locate.
04 / 05	Statutory collection period expired (04 on a portion; 05 on the whole).
06	International—taxpayer residing outside the U.S.
07 / 10 / 13	Corporate—bankrupt/insolvent (07), defunct (10), or in-business (13).
08	Decedent case.
09	Tolerance (balance too small to pursue).
12	Unable to contact.
14	Combat zone.
24–32	Hardship CNC—unable to pay, graduated by Total Positive Income ($20,000 at CC 24, up to $84,000+ at CC 32).
39	IDS/ACS/IQA hold—requires National Office authorization.

The CNC you'll most often see on pro se transcripts is a hardship CC in the 24–32 range. The CSED keeps running in CNC status. If the 10 years CSED expires while you are in CNC, the balance gets written off (see TC 608).

TC 531 reverses CNC status. TC 532 marks a TC 530 posted in error. TC 537 is system-generated when a subsequent return shows income high enough to reissue collection.

Lien Codes

Code	What It Means
TC 582	Lien indicator—a federal tax lien has been filed for this tax period.
TC 583	Reverse lien indicator. Releases the lien. Carries a Definer Code: DC 1 = released; DC 2 = withdrawn for administrative error; DC 3 = withdrawn due to CDP; DC 4 = reversal; DC 5 = self-released (CSED expired).

A TC 582 with no matching TC 583 is an active lien. A TC 583 with DC 5 is the self-release triggered when the CSED runs out.

Statute Expiration (CSED Write-Off) Codes

Code	What It Means
TC 604	Assessed debit cleared—triggered by bankruptcy discharge (paired with TC 971 AC 031) or accepted OIC (paired with TC 971 AC 032). Not the CSED-expiration code.
TC 605	Reversal of TC 604 (matching TC 972 AC 031/032).
TC 608	Statute expiration clearance to zero balance. System-generated when the CSED expires with a debit balance. The IRS's own marker that the debt is legally gone.
TC 609	Reversal of TC 608 if a subsequent money transaction posts or the CSED is extended.

If you've been in CNC status for years and the 10 years CSED runs out, you're looking for TC 608, not TC 604. TC 604 means something different closed out the balance (bankruptcy discharge or accepted OIC). Both codes zero the balance, but only TC 608 reflects CSED expiration under IRC § 6502.

TC 608 is the moment the 10 years CSED under IRC § 6502 gets enforced against the IRS. If TC 608 posts and the IRS keeps collecting, you have grounds for a Form 843 claim to recover amounts collected after the CSED ran.

Notice and Admin Codes

Notices sent, representatives added, and miscellaneous actions live here.

TC 922—AUR (Automated Underreporter / CP2000)

TC 922 means the AUR program flagged an income mismatch—typically a 1099 or W-2 that doesn't match your return. An open TC 922 with no resolution means a CP2000 process is active. TC 924 and TC 925 are related AUR communication postings. You have 30 days from the CP2000 notice to respond. See How To Respond to a CP2000 Notice.

TC 960 / 961—Power of Attorney

Code	What It Means
TC 960	CAF indicator added. Form 2848 (POA) or 8821 (TIA) is on file; notices now route to your representative.
TC 961	Reverse CAF indicator. Authorization removed.

TC 971—Miscellaneous Transaction (with Action Codes)

TC 971 is a catch-all. Its real meaning depends on the three-digit Action Code (AC). Document 6209 Section 8C lists hundreds; these are the ones most relevant to pro se readers:

AC	What It Means
001 / 002	TC 150 or amended/duplicate return posted to incorrect TIN or tax period.
010–015	Amended return/claim forwarded to Accounts Management (010), Collection (012), Examination (013), Statute Control (014), or Underreporter (015).
031	Full bankruptcy discharged.
032	Fully accepted OIC.
033	Partial bankruptcy abatement.
043	Pending installment agreement.
044	CP 05 issued (refund review).
065	Request for Innocent Spouse Relief (Form 8857) received. Generates an L- freeze.
069	Due Process Notice issued—the CDP notice (Letter 1058 / LT11 for levy; Letter 3172 for lien).
073	Open under the SS-8 program (worker classification).
081	Update of the Control DLN (generates CP 276).
086 / 087	Disaster FTF/FTP suspension (086 normal; 087 with § 7508(a) relief).
100 / 101	Bankruptcy or OIC case (causes MFT 31 or MFT 65 creation).
107 / 108 / 109	One-spouse IA request (107), CDP hearing request (108), or CNC (109).
141	ASFR (Automated Substitute for Return) posted.
275	Timely CDP request received. Module excluded from automated levy programs.
276	CDP issue resolved by ACS or Field Collection (not sent to Appeals).
277	Appeals CDP determination letter issued.
278	Equivalent CDP hearing received (does not exclude automated levy).
501 / 506 / 522	Identity theft indicators and documentation.

TC 972 reverses a prior TC 971—if you see a TC 971 with an AC followed by a TC 972 with the same AC, the original action was reversed.

Common Patterns

Codes tell a story in sequence. The patterns you'll most commonly see:

Pattern 1: Clean Filer, Refund Paid

TC 150  Return filed
TC 806  Credit for withheld taxes
TC 766  Refundable credit (EITC, CTC, etc.)
TC 846  Refund of overpayment

The happy path. The date next to TC 846 is when the refund was scheduled.

Pattern 2: Audited With a Deficiency

TC 150  Return filed
TC 420  Examination opened
TC 300  Additional tax assessment by Exam/Appeals
TC 196  Computer-generated interest
TC 421  Examination closed

Audited, deficiency determined, interest added, case closed.

Pattern 3: Notice of Deficiency → Tax Court Petition

TC 494        Notice of Deficiency issued
TC 520 cc 72  Tax Court case (—W freeze)

The IRS confirmed both the SNOD and your petition. The —W freeze suspends collection on the deficiency under IRC § 6213(a). The petition deadline is 90 days from the SNOD date (150 days if outside the U.S.). See You Just Got a 90-Day Letter from the IRS.

Pattern 4: Offer in Compromise Accepted

TC 480  Offer-in-Compromise pending
TC 780  Master File Account Compromised (OIC accepted)
TC 788  All collateral conditions completed

If rejected: TC 481 (rejected, processable), TC 482 (withdrawn), or TC 483 (not processable). See How To Apply for an Offer in Compromise.

Pattern 5: CSED Expired—Debt Legally Gone

TC 150           Return filed (assessment posted)
TC 530 (any CC)  CNC at some point
TC 608           Statute expiration clearance to zero
TC 583 with DC 5 Lien self-released

The 10-year CSED ran out. Balance zeroed; any lien self-released. See Understanding IRS Statutes of Limitations.

Pattern 6: CDP Request Filed

TC 971 AC 275     Timely CDP request received
TC 520 cc 76 / 77 CDP lien or levy freeze (CSED suspended)
TC 971 AC 277     Appeals determination issued
TC 521            Reversal of TC 520 (case closed)

CDP recorded, collection suspended, Appeals determination. See Collection Due Process Hearings.

Pattern 7: CP2000 Active

TC 922            AUR underreporter open
TC 290 or TC 300  Adjustment (or $0 if no change)

AUR flagged an income mismatch. A CP2000 carries a 30-day response window—see How To Respond to a CP2000 Notice.

Pattern 8: Amended Return Posted

TC 977            Amended return posted
TC 971 AC 010     Routed to Accounts Management
TC 290 or TC 291  Adjustment (or abatement)

Your 1040X is on the Master File. The next TC 29X shows what the IRS did with it. See How To File an Amended Return.

Pattern 9: Installment Agreement in Place

TC 971 AC 043    Pending installment agreement
TC 670           Monthly IA payment posted
TC 670           Monthly IA payment posted

Status codes 60–64 on the module (visible on a practitioner TXMODA, not the taxpayer Account Transcript) indicate an accepted IA. For a taxpayer, the practical signals are the initial TC 971 AC 043 marker plus a sequence of regular TC 670 payment postings and the absence of any TC 971 AC 063 ("Termination of IA"). See How To Set Up an IRS Installment Agreement.

Codes That Should Trigger Action

If you see any of these on your own transcript, they carry a deadline, a statute implication, or a right you should act on.

TC 494—the 90-day clock is running. 90 days from the SNOD date to petition Tax Court (150 days if outside the U.S.). Miss it and you lose the prepayment forum. See You Just Got a 90-Day Letter and You Missed the Deadline—Now What.
TC 971 AC 069—CDP notice issued. 30 days to file Form 12153 to preserve CDP rights.
TC 922 with no resolution—AUR is working your case. A CP2000 carries a 30-day response window.
TC 582 with no matching TC 583—active federal tax lien. Check the filing date against the CSED.
TC 608—CSED expired; balance written off. If the IRS keeps collecting, the action is improper under IRC § 6502.
TC 971 AC 141—ASFR posted. Filing your own original return usually overrides the SFR with real numbers.
TC 290 at $0—almost certainly not a new assessment. See the callout above.

What Codes Don't Tell You

The account transcript shows postings—not narratives. Even fully decoded, the transcript will not show:

Specific audit adjustments item by item—AMDISA and RTVUE (practitioner-only).
Appeals case status and history—AMDISA.
Penalty calculation methodology—PINEX (practitioner-only).
Correspondence with IRS Counsel or settlement discussions—case file only.
IRS Collection's internal history log (ICS narrative)—FOIA required.

If your situation needs any of those, see How To Get and Read Your IRS Transcripts for the practitioner-only transcripts. A Low Income Taxpayer Clinic can pull these at no cost for taxpayers whose income is at or below 250% of the poverty line with a dispute under $50,000 per tax year.

Resources

Primary sources:

Companion articles:

This article is for informational purposes only and does not constitute legal or tax advice. For advice specific to your situation, consult a qualified tax professional or attorney.