Two different things
A claim for refund "Must involve an overpayment ... To request a refund or credit of an overpayment, the taxpayer must file a valid claim before the Refund Statute Expiration Date (RSED)." An abatement request "results in an accounting decrease in an assessed tax and/or penalty liability that remained unpaid," and "The Internal Revenue Code (IRC) does not provide a specific right to file a claim for abatement" (IRM 21.5.3.2, Feb. 2, 2024).
IRM 21.5.3.2 (Feb. 2, 2024); 21.5.3.4.6, 21.5.3.4.6.1, 21.5.3.4.6.3 (June 11, 2026).
The authority for the abatement route is IRC 6404(a), which lets the IRS abate "the unpaid portion of any assessment which is: Excessive in amount, Assessed after the expiration of the applicable limitations period, or Erroneously or illegally assessed" (IRM 21.5.3.2, Feb. 2, 2024). A 972CG response, a CP15 reply and a Form 843 marked "abatement" on an unpaid penalty are all abatement requests. A Form 843 for a penalty you paid, or a Form 945-X claiming a withholding overpayment, is a claim. Informal claims count if written: "An informal claim must have a written component apprising the IRS that a refund is sought and describe the legal and factual basis for the refund so that the IRS may investigate the claim" (IRM 25.6.1.10.3.2.3, July 5, 2024).
One trap sits between the two. "If a request for abatement is filed and the module balance becomes partially or fully paid at a later date, continue to treat it as a request for abatement unless a new, timely claim for refund is filed" (IRM 21.5.3.2 Caution). Paying a penalty to stop the CP504 sequence while your abatement request is pending does not convert the request into a claim; if the request is denied, you have to file the claim separately, inside the refund statute, to preserve the right to sue.
The abatement request
"A request for abatement is a request for reduction of tax, penalty, and interest that has not been paid. This includes penalty adjustment requests. Do not follow no consideration procedures and do not deny requests solely for nonpayment of tax. Process the claims using normal adjustment procedures" (IRM 21.5.3.4.6, June 11, 2026). You do not have to pay a 972CG penalty to have it reconsidered.
Abatement requests are worked "using normal adjustment procedures," and where the request "contains sufficient documentation/explanation to support the adjustment" and meets examination criteria it is forwarded to Exam classification (IRM 21.5.3.4.6, June 11, 2026). For information-return penalties the substantive standard is the one in the 972CG examiner guide; this page is about the procedural wrapper. Two procedural points matter. Because no refund is involved, the refund statute does not apply ("If the taxpayer requests an adjustment that does not create an overpayment, then IRC 6511 does not apply," IRM 25.6.1.10.3.3 Note). And because the Code gives no right to a claim for abatement, a denial carries appeal rights within the IRS but no route to court until the penalty is paid.
The paragraph in every denied abatement request: "If you disagree with our determination and want to file a suit in court, you must first pay the tax you owe and then file a claim for refund. Your claim must generally be filed within 3 years from the date you filed your return or 2 years from the date you paid your tax, whichever is later" (IRM 21.5.3.4.6.1, June 11, 2026).
That paragraph is required in the letter: "When disallowing a request for abatement, inform the taxpayer that they may pay the tax due and file a claim for refund" (IRM 21.5.3.4.6.1). It is also the map. Pay, then file Form 843 as a claim, within three years of the return or two years of the payment, and the denial of that claim is what opens the courthouse.
The claim for refund
A claim must be timely under IRC 6511 and must state its basis. The forms: "Form 843, Claim for Refund and Request for Abatement, is the general form for claiming a refund" of penalties, and "Employment Tax is filed on the 'X' form to which the original return relates," which for backup withholding is Form 945-X (IRM 25.6.1.10.3.2.2.2, July 5, 2024). Claims are screened against statute rules first: "Do not allow a claim for refund if the claim for refund is received after RSED has expired, even if the claim contains an issue that the taxpayer has a right to appeal" (IRM 25.6.1.10.3.1.3). The statute page has the deadlines and look-back rules.
A claim that is complete and timely but not allowed is disallowed with appeal rights. One that is incomplete is not disallowed; it is set aside: "Taxpayer did not respond to a request for missing information: Treat claim as a no consideration" (IRM 21.5.3.4.6 row 8). The manual's caution to its own staff is worth knowing: "Only disallow claims after complete research and all contacts have been made for any missing information" (IRM 21.5.3.4.6 Caution).
105C, 106C and 916C
Letter 105C, Claim Disallowed, is used for a full disallowance and also "if partially disallowing a claim results in a balance due or zero-balance." Letter 106C, Claim Partially Disallowed, is used when the partial disallowance still leaves a refund (IRM 21.5.3.4.6.1, June 11, 2026). Both "are sent certified or registered mail," "must be reviewed by the Lead and/or Manager within two business days," and "must contain the specific reason for the disallowance of the claim for refund or request for abatement as well as the claim amount," a requirement the manual ties to IRC 6402(l) (IRM 21.5.3.4.6.1). A statute-based disallowance "must include the received date of the original/amended return or postmark date of the envelope and the date the claim should have been filed to be considered timely" (IRM 21.5.3.4.6.1 Note). A 105C that gives no reason, or no amount, does not meet the manual's own standard.
Letter 916C, Claim Incomplete for Processing; No Consideration, is the other outcome. It "is used for 'no consideration' or rejected claims," it "must advise the taxpayer why the claim is not being considered," and "AM employees do not send the Letter 916C by certified mail" (IRM 21.5.3.4.6.3, June 11, 2026). The legal difference is decisive: "a 'no consideration' letter is not a disallowance letter" (IRM 25.6.1.10.3.1.3), so it starts no clock to sue and leaves the claim open. When the suit period has already run on an earlier disallowance, the 916C carries fixed language: "When the period of time to file suit has expired, we can no longer consider your claim. For more information, please refer to your original disallowance notice."
Replying to a disallowance
"A response to Letter 105C, Claim Disallowed, and Letter 106C, Claim Partially Disallowed, is treated as a new case" (IRM 21.5.3.4.6.2, June 11, 2026). The table that follows is the whole decision tree. Resubmit the same claim with nothing new: the assistor re-checks the disallowance, and if "documentation, such as IRPTR, etc., is now available to substantiate the claim," allows it; otherwise "close the case as a no consideration" (row 1). Send new information that supports the claim: "normal adjustment procedures" (row 2). Send new information that still does not get there: "Do not send another disallowance letter," but a 916C explaining "what additional information is needed" (row 3). Ask for an appeal in writing: the case goes to Appeals electronically (row 4). The one thing a second letter cannot do is restart the suit period: "Any reconsideration by the IRS does not extend the time for bringing suit" (IRM 21.5.3.4.6.2).
The certified 105C or 106C is therefore the document to calendar. "The 2-year period for bringing a refund suit begins on the date the IRS sends (by certified or registered mail) a notice of disallowance ... The 2-year period can be extended in writing between the IRS and the taxpayer. The IRS uses Form 907" (IRM 21.5.3.4.6.2). After it ends, "IRC 6514, Section (a)(2) prohibits the IRS from issuing a refund after the two-year period for filing a refund suit expires unless the taxpayer has brought a timely suit," and the manual's caution extends that to claims that reached Appeals late: "Even if the taxpayer filed the claim timely, but the claim was sent to Appeals after the 2-year period has expired, the IRC 6532 statute prevents the refund from being released" (IRM 21.5.3.4.6.2 and Caution).
Appeals and the 120 days
"If the taxpayer calls in regarding their 105C/106C response, provide the 120-day appeal timeframe"; once forwarded, "Appeals typically contacts taxpayers within 120 days of receipt. If the taxpayer has not been contacted within this time frame, send a Form 4442 to appeals" (IRM 21.5.3.4.6.2, June 11, 2026).
The appeal request is a written statement; the assistor must forward "the taxpayer's original disallowed claim and the taxpayer's original return (or return print), copy of disallowance letter, and taxpayer's statement of appeal," and the packet goes through a campus Appeals coordinator to Appeals' electronic case receipts (IRM 21.5.3.4.6.2, June 11, 2026). A claim resubmitted "without new or additional information" after a correct disallowance is not sent back to Appeals a second time; the taxpayer gets a letter saying "the same claim was previously submitted" (IRM 21.5.3.4.6.2 Note). The penalty-specific appeal routes, including the Letter 854-C reconsideration step that precedes Appeals for 972CG denials, are on the after-the-denial guide and the Appeals guide.
Audit reconsideration: the third route, for an examination assessment
A Form 945 assessment that came from an examination rather than a notice has its own reopening procedure. "An audit reconsideration is the process the IRS uses to reevaluate the results of a prior audit where additional tax was assessed and remains unpaid, or a tax credit was reversed. If the taxpayer disagrees with the original determination, they must provide new information for the audited issue(s) not previously considered during the original examination" (IRM 4.13.1.2, Dec. 10, 2025). The criteria are cumulative: "The taxpayer must have filed a tax return and The assessment remains unpaid ... and The taxpayer must identify which adjustments they are disputing and The taxpayer must provide new additional information for the audited issues not considered during the original examination or There was an IRS computational or processing error" (IRM 4.13.1.2.1). New information is the hinge: Forms 4669 and 4670 secured after the examination closed, a W-9 located after the report, or a payee's return showing the income was reported all qualify; re-arguing the same facts does not.
For a business the request "go[es] through Exam Classification. Accounts Management works non-selected cases" (IRM 21.5.10.4.3, Oct. 23, 2025), and an allowance posts as a TC 291 abatement. Some doors are closed: the IRS "won't reopen" cases "decided by the U.S. Tax Court," closed by a Form 906 or 866 closing agreement, or settled in Appeals on a Form 870-AD or 2504-AD, "or when a statute of limitation prevents the reopening of the issue" (IRM 4.13.1.4.5). A business that signed Form 2504 at the examination may still seek reconsideration with new information; one that settled in Appeals on an "AD" form may not. If the assessment has been paid in full the route is a claim, not a reconsideration: "If the account has been full paid ... tell the TP they do not qualify for a reconsideration, but they may be eligible to file a claim" (IRM 4.13.1.3.1). Where a reconsideration request is denied, Appeals rights follow as for any examination (IRM 4.13.1.4.5).
Can you see the IRS's file on your penalty?
Yes, with limits, and the request is a Freedom of Information Act request rather than a phone call. Your own penalty case is your return information, and an information return "is considered the return information of both the payor and the payee" (IRM 11.3.2.5.3, Sept. 17, 2020), so the data behind a 972CG is yours to see. Other payees' return information is withheld under FOIA exemption (b)(3), which protects material "specifically exempted from disclosure by statute," with "IRC 6103 (most commonly used)" (IRM 11.3.13.4.2.4, Oct. 6, 2025); you get their names and TINs as they appear on your own filings, not their accounts.
Two other exemptions explain what comes back redacted. Exemption (b)(7)(A) covers records "compiled for law enforcement purposes" whose release "could reasonably be expected to interfere with enforcement proceedings," and "is commonly applied to open Criminal Investigation, Examination, Collection, Appeals, and Counsel files" (IRM 11.3.13.4.2.8.1, Oct. 5, 2021). A penalty case still in Appeals is largely closed to you until it is decided. Exemption (b)(7)(E) protects "techniques and procedures for law enforcement investigations" and "has been applied to protect DIF, DAS and UIDIF scores, tolerances, and investigative criteria" and "Settlement criteria or records that discuss hazards of litigation" (IRM 11.3.13.4.2.8.5, Oct. 5, 2021). That is the exemption behind every run of ≡ symbols in the public Internal Revenue Manual pages linked from this site: the penalty tolerances in IRM 20.1.7, the non-assertion thresholds in 5.7.4, the verification ratios in 21.6.3. They are not missing by accident, and a FOIA request for your file will not produce them either.
An adverse answer, including "no responsive records exist," comes with Notice 393 appeal rights: an administrative appeal to the Independent Office of Appeals within at least 90 days, plus mediation through the IRS FOIA Public Liaison or the Office of Government Information Services (IRM 11.3.13.5.3, Oct. 6, 2025). There is no administrative appeal for a late response, only court. A request for your own account transcript is not a law-enforcement record and is better made through the transcript routes described on the calling guide than through FOIA.
What to put in the letter
- Say which one it is. "Request for abatement under IRC 6404(a) of the unpaid penalty assessed on [date]" or "Claim for refund of penalty paid on [date]." If the penalty is paid, use Form 843 and check the claim box; for Form 945, use the 945-X with the claim box.
- State the legal and factual basis. That is what makes an informal claim a claim, and it is what the examiner needs to decide. For information-return penalties the facts are the solicitation record; the reasonable-cause statement template is built for it.
- Sign it. Unsigned claims are returned for signature, and the time runs while they sit (IRM 21.5.3.4.4).
- Answer every request for information. Silence produces a 916C, and a 916C followed by resubmission after the statute produces a 105C that cannot be undone.
- Calendar the certified letter. Two years from the postmark of a 105C or 106C, extendable only by Form 907 signed before the date.
Questions people ask
We answered the 972CG, lost, and the CP15 arrived. Do we have to pay before we can argue again?
No. A reply to the CP15 is an abatement request on an unpaid penalty; the manual tells assistors not to deny it for nonpayment (IRM 21.5.3.4.6). What you cannot do without paying is go to court. The denial letter will say so and will tell you to pay and file a claim.
We paid the penalty while the abatement request was pending. Is our request now a claim?
Not automatically. It stays an abatement request "unless a new, timely claim for refund is filed" (IRM 21.5.3.2 Caution). File Form 843 as a claim for the amount paid, within the refund statute, so that a later denial comes as a certified 105C with suit rights.
The letter we got is a 916C. Did we lose?
No. A 916C means the claim was not considered, usually for missing information, and it is not sent certified and is not a disallowance (IRM 21.5.3.4.6.3; 25.6.1.10.3.1.3). Send what it asks for. The claim remains open and the suit clock has not started.
How long does Appeals take?
The figure assistors give is 120 days from Appeals' receipt to first contact, and a Form 4442 referral goes in if that passes (IRM 21.5.3.4.6.2). Appeals' own timeframes for penalty cases are on the Appeals guide.