What happens to your letter at the IRS: the 30-day clock, interim letters and Form 4442

The standard: Action 61 and Policy Statement P-21-3

The rules for answering taxpayer letters descend from a review of "Corporate Critical Success Factor 61," which the manual still calls the Action 61 standard, and were written into Policy Statement P-21-3, formerly P-6-12 (IRM 21.3.3.1.8, Oct. 1, 2023). A quality response "is accurate, timely, and addresses all issues based on the information provided" and is "written in language the taxpayer can understand" (IRM 21.3.3.1.8). Where a Code provision and P-21-3 conflict, "IRC governs" (IRM 21.3.3.1.9, May 5, 2025). The standard measures whether the IRS wrote back, not whether it agreed, and it belongs to Accounts Management (AM); a letter AM forwards to a penalty function picks up that function's clock instead (see routing).

The 30-day clock, 14-day control and 45-day aging

The core sentence: "Final response to taxpayer(s) must be initiated by the 30th day from the earliest IRS received date, unless the taxpayer has received an interim contact or interim contact has been initiated from the IRS by the 30th day" (IRM 21.3.3.1.9, May 5, 2025); "Whenever possible, issue a response in less than 30 days" (IRM 21.3.3.3.4(7), Dec. 19, 2023). Three words matter. "Earliest" means the first IRS stamp, wherever your envelope first landed. "Initiated" means the letter was requested in the system; letters are dated "three to five working days" after input (IRM 21.3.3.4.22(1)(a), Oct. 1, 2019), so the printed date is later than the day the assistor wrote it. And "interim" means the clock is satisfied by a letter that answers nothing.

Before the reply there is a control. "Open cases must NOT remain uncontrolled more than 14 days from receipt at IRS" (IRM 21.3.3.4(1), Oct. 1, 2023; IRM 21.3.3.4.1(5), Nov. 22, 2022). Once controlled, correspondence carries a "45-day aging criteria," and the manual forbids changing the category code to escape it (IRM 21.3.3.4.1(6), Nov. 22, 2022). While the case sits in inventory, balance-due notices are suppressed with CC STAUP or TC 470 (IRM 21.3.3.4.1(7)); a penalty bill that goes quiet after you write is suppressed, not decided. When the reply comes it may be a notice: a CP 21 series, CP 22A, CP 210, CP 220 or CP 225 can substitute for a closing letter if it answers everything raised (IRM 21.3.3.3.4(4), Dec. 19, 2023). A written response is required regardless of P-21-3 status when a penalty is abated under First Time Abate or sustained (IRM 21.3.3.4.16.3.1(3), Dec. 19, 2023).

Interim letters: 2645C, 2644C and 86C

"An interim letter is required to be sent within 30 days of the received date if a final response cannot be issued" (IRM 21.3.3.4.2.2(1), June 2, 2023). Every interim letter must state when to expect final resolution, and the promised date "does not have to be in increments of 30 days" (IRM 21.3.3.4.2.2(2)). The first interim is typically Letter 2645C. If the promised date passes, "a subsequent interim letter, for example, the 2644C Letter, Second Interim Response, must be issued," and it "must include the specific reason for the delay" (IRM 21.3.3.4.2.2(4)). Once any interim has gone out a closing letter must follow unless the closing action itself generates a notice (IRM 21.3.3.4.2.2(6)). Since January 2018, AM interim letters generated through CII and AMS systemically promise 60 days rather than 45 (IRM 21.3.3.4.2.1(3), Nov. 22, 2022): read a 2645C as "about 60 more days," or roughly 90 days from your received date before the IRS is late on its own promise.

Letter 86C is different in kind. It is the interim letter used when the case is transferred to another office outside the directorate; AM tells the taxpayer "an additional 60 days is needed," and the receiving office owns the final reply (IRM 21.3.3.4.2.1, Nov. 22, 2022). An 86C means your letter has left Accounts Management. A Form 4442 referral carries the same 30-calendar-day written reply standard (IRM 21.3.3.4.15(4), Oct. 1, 2019).

What counts as correspondence, and what does not

"Correspondence is all written communications initiated by a taxpayer or taxpayer representative, excluding tax returns, whether solicited or unsolicited" (IRM 21.3.3.2(1), Oct. 1, 2025). It includes written responses to IRS requests for information, "annotated notice responses" that add information or dispute a notice, and "a telephone call that results in a written referral or research (Form e-4442)." The three test questions are whether the taxpayer is waiting for a response, waiting for an action, or asking a question (IRM 21.3.3.2(2)); a CP2100 or 972CG reply that disputes a listing or adds facts passes all three.

The exclusion list (IRM 21.3.3.2(3), Oct. 1, 2025) is where payer mail goes wrong. Amended returns and "Form 94XX" are excluded, so a Form 945-X mailed on its own has no P-21-3 reply clock. "All extensions to file: Form 4868, Form 7004, and Form 8868" are excluded; Form 8809 is not named either way. CAF and power of attorney submissions, "Address Changes," "Correspondence received only indicating a payment made," replies to IRS solicitations "necessary to secure or complete the processing of a tax return," and "Incoming replies from a third party (e.g., state certifications, Federal Tax Deposit (FTD) verification, etc.)" are all excluded. A call answered on the line is excluded; if it needs research, "the Form 4442 becomes correspondence for the purpose of Policy Statement P-21-3." The practical rule: if you want the 30-day clock, write a letter that asks for or disputes something and attach the form to it. A bare 945-X, payment or Form 8822-B does not enter the correspondence inventory.

The date the IRS quotes back to you

When the IRS writes "your letter dated ...," it is using the correspondence date, chosen in this order (IRM 21.3.3.4.2.3(5), Oct. 1, 2026): the date the taxpayer's "correspondence was prepared or signed"; the "Transmission date on a fax or electronic submission receipt"; the envelope postmark; the SCAMPS digital date stamp on the envelope; "Three calendar days prior to the IRS received date of the case" (this revision clarified calendar days); the current date; and, for Taxpayer Assistance Center walk-ins only, the IDRS received date. "Don't use the IRS received date as the correspondence date unless otherwise noted" (IRM 21.3.3.3.4(3), Dec. 19, 2023); for a fax, "use the date the fax was transmitted to us" (IRM 21.3.3.4.16.3(6)(a), May 5, 2025). Date and sign every letter; an undated one in a lost envelope is dated three days before the IRS stamp. The manual names no online upload channel; "electronic submission receipt" is the only phrase covering uploads.

The date has a visible effect. When an adjustment is input with a correspondence date, the resulting notice adds "This is the result of your inquiry of (fill in)"; otherwise the notice is identical (IRM 21.3.3.4.2.3(6), Oct. 1, 2026). The BMF trap: "when there is no monetary adjustment (e.g., TC 290 .00, TC 180 .00) or when no notice will be generated, it is not a requirement to input the correspondence date" (IRM 21.3.3.4.2.3(4) row 5, Oct. 1, 2026). A payer's dispute closed with no money change may produce a notice that never mentions the letter, or no notice at all unless another rule requires one.

What a penalty letter must say

When a letter explains a penalty, the manual requires four elements: "The dollar amount of the penalty including accruals," "The title (name) of the penalty," "The Code section under which the penalty was assessed," and the dollar amount of interest including accruals (IRM 21.3.3.4.2.2.1(4), Oct. 1, 2025). A denied reasonable-cause request must also contain everything IRM 20.1.1.3.5.3(5) requires. A penalty letter missing the Code section or the accrued interest is one you can fairly ask to have completed.

If a current balance cannot be given, the letter must say a notice will issue "within 4 to 6 weeks" (IRM 21.3.3.4.2.2.1(6)). A payment enclosed with correspondence must be acknowledged if no notice will address it (IRM 21.3.3.4.2.2.1(8)).

Where a civil penalty request goes: expect a Letter 86C

AM does not work every penalty letter it receives. "Penalty Abatement requests such as Civil Penalties ... will be routed to the appropriate area that assessed the penalty. See IRM 20.1.1-4, Penalty Reference Numbers (500 Series), or IRM 20.1.1-5, Penalty Reference Numbers (600 Series)" (IRM 21.3.3.4.8.2.1(5), Apr. 1, 2026). An information-return penalty under IRC 6721 or 6722 carries a 500-series reference number, so an abatement request that reaches Accounts Management is forwarded to the function that assessed it rather than worked as an account case. Because the transfer leaves the directorate, expect Letter 86C saying "an additional 60 days is needed," with the receiving office owning the reply (IRM 21.3.3.4.2.1, Nov. 22, 2022). The penalty reference number decoder identifies the series, and the 854C reconsideration guide covers what the assessing function does next.

As of January 5, 2026, "Accounts Management (AM) no longer prepares Form 911 or Form e-911 for taxpayers meeting TAS criteria" (IRM 21.3.3.4.8(2), Jan. 9, 2026); a payer who wants the Taxpayer Advocate goes to TAS directly.

Who may write: letterhead, faxes, signatures and Letter 135C

Before replying, AM checks the CAF and RAF for third parties, and an authorized reporting agent "will receive duplicates of what is sent to the taxpayer" (IRM 21.3.3.4.16.4(9)-(10), Oct. 1, 2025). An unauthorized third party who wants an answer gets Letter 135C, "Power of Attorney Needed to Furnish Information," and the taxpayer gets a letter explaining why. Then comes the exception that matters for a business.

"IRC 6061 requires original signatures on returns and in certain other situations," but "The IRS's Fax Policy allows us to accept a faxed signature in many instances when we make taxpayer contact" (IRM 21.3.3.4.8(9), Jan. 9, 2026), so a faxed reply to an IRS letter is generally acceptable. An address change "NOT signed by the taxpayer or authorized representative" is not acted on; AM sends Letter 104C with Form 8822 or 8822-B information and "the paragraph stating the form MUST be signed" (IRM 21.3.3.4(6), Oct. 1, 2023), and "Due to the high level of identity theft" records the requester's name and title (IRM 21.3.3.4(5)).

On the IRS side, "Signatures on outgoing letters are mandatory" (IRM 21.3.3.4.19(9), Oct. 1, 2026), but a letter with no named contact is not defective: RRA 98 section 3705 requires a name, phone and employee ID on "manually generated correspondence," and "Correspondex letters (C letters) are not considered manually generated correspondence and therefore contact information is not required" (IRM 21.3.3.4.16.1, May 5, 2025; IRM 21.3.3.4.16.4(6), Oct. 1, 2025). A Letter 147C with nobody's name on it is normal.

The header block the IRS wishes you would use

The manual encourages reference lines in outgoing letters "particularly ... in the case of large corporations or tax practitioners who may have several matters pending," with the example "Your letter dated 10/11/23, Payroll Div.; P.D.S.; Re: John Doe, 000-00-0000" (IRM 21.3.3.4.16.3(6)(b)-(c), May 5, 2025), and its standard closing request is "When you reply, please send us your telephone number and most convenient time for us to call" (IRM 21.3.3.4.16.3(8)). Turned around, that is the header the assistor is looking for:

Form 4442 referrals: 30 calendar days, then an apology

A phone call is not correspondence until it fails. When an assistor cannot resolve an inquiry on the phone, in a Taxpayer Assistance Center, in Live Chat, or by close of business, a referral is initiated "in limited instances"; the assistor is told to "Offer to prepare a referral and advise the taxpayer of the 30 day timeframe" (IRM 21.3.5.2(1), June 15, 2026). The promise is "tell the taxpayer they will hear from us within 30 calendar days," and the timeframe "is for contact or resolution" (IRM 21.3.5.4(1), May 28, 2025): a call back with a question is timely. Not a referral: "A fax from a taxpayer or any written correspondence," transferring a call, giving out a phone number, or directing someone to a TAC (IRM 21.3.5.2.1, June 15, 2026); letters and faxes are worked under IRM 21.3.3. No referral is made for a pure status check "if the taxpayer ... does not provide additional information" (IRM 21.3.5.2(4)). A referral is required when the assistor is not trained on the issue, when a subject-specific manual directs it, or when an open control blocks action (IRM 21.3.5.4.1, Oct. 1, 2026).

The mechanics: AMS blocks a duplicate referral created within the past 7 calendar days for the same TIN, MFT, tax period, function, issue and site (IRM 21.3.5.4.2.1.1(1), June 15, 2026). A manager reviews "within three (3) business days," and transmission to the receiving point happens "within four (4) days" (IRM 21.3.5.4.2.1.1(6),(9); IRM 21.3.5.4.3(1)). The referral "is considered aged if there is no response, action, or resolution by the 30th calendar day from the inquiry or last action date" (IRM 21.3.5.4.6.3). A generated notice counts as closure "if it clearly 'responds to' or addresses the taxpayer's inquiry" (IRM 21.3.5.4.6.4, Mar. 6, 2019).

The same table gives the other two outcomes: with an open control, expect contact within 30 days of receipt; with a closed control, "expect correspondence within two weeks of the closing date," and "Never send a referral to an assistor after a case has been closed" (IRM 21.3.5.4.2.1.1.1(2), June 15, 2026). The referral exhibit routes "Backup Withholding-'C' Indicator" questions to IRM 5.19.3.5.2.2, "Duplicate EIN" to IRM 21.7.13.6.3, "Form 1042-S" to IRM 21.8.2.12.2.5 (FATCA matching credit reversals, Letter 5532C), unpostables open 8 weeks or more to IRM 21.5.5.3.3, and "Transfer Between Agents, Practitioner Priority Service Only" to IRM 21.3.10.5 (Exhibit 21.3.5-1, Oct. 1, 2026). It has no row for CP2100 or Notice 972CG. See the calling-the-IRS guide and the C-notice guide.

Routing facts for payers

When an IRS letter asks you for something, "A 45-day suspense period is the standard for unanswered letters" (IRM 21.3.3.5.1.1(1), Mar. 19, 2015). A reply arriving after that is stamped "Late Reply" and routed to the originating area with the instruction "If the taxpayer provides the requested information, stop the notice if it has not been issued" (IRM 21.3.3.4.9(1),(5), Oct. 1, 2012).

Questions people ask