Letter 2644C: Second interim response: the promised date was missed, with a stated reason

What Letter 2644C is

Sent when the date promised in the first interim letter passes without a final answer. The manual says a "subsequent interim letter, for example, the 2644C Letter, Second Interim Response, must be issued if a final resolution cannot be provided by the promised date" and that it "must include the specific reason for the delay" (IRM 21.3.3.4.2.2(4), June 2, 2023). Like the 2645C it must give a new date for the final response and, unless systemically generated, a contact name, telephone number and employee ID (IRM 21.3.3.4.2.2.1, Oct. 1, 2025).

The deadline

No action required. A new resolution date is stated in the letter; it "does not have to be in increments of 30 days" (IRM 21.3.3.4.2.2(2)).

What to do

Read the reason given. If it says the case was sent to another office, the letter you should have received is a Letter 86C, and the receiving office now owns the reply (IRM 21.3.3.4.2.1, Nov. 22, 2022). If no reason is stated, the letter does not meet the manual's requirement and you can say so when you call. Do not send a duplicate of your original letter; a second letter on the same period is answered together with the first (IRM 21.3.3.4.2.3(9), Oct. 1, 2026).

Why cases run past the promised date

Correspondence at an IRS campus is worked from inventories, and a case can stall for reasons that have nothing to do with its merits: the inventory it sits in is behind, it was routed to the wrong function and has to be re-routed, it needs a record from another office, or the penalty it concerns was assessed by a unit that Accounts Management must forward it to. Letter 2644C is the second interim letter, issued when the date promised in the 2645C has passed, and the one thing that distinguishes it from the first is that it is supposed to say why. The reasons are usually short: additional research is required, the case has been referred to another area, or a backlog. It also gives a new date, which need not be another 60 days.

A 2644C is not a bad sign about the outcome. It is a bad sign about the timeline, and the right response is to protect your position while you wait rather than to send more paper.

Protecting your position while you wait

Do not send a duplicate of the original letter; a second letter on the same matter is attached to the first and worked together with it, and can push the case back in the queue. Do keep paying anything that is not in dispute, because interest and failure-to-pay penalties run on an unpaid balance regardless of an open correspondence case, and collection notices can continue to issue in parallel; if a CP504 arrives while a 2644C is outstanding, call and ask for a collection hold citing the open case. If the stated reason is a transfer to another office, the next letter you should have is a Letter 86C naming that office. If the new promised date also passes, the Taxpayer Advocate Service accepts cases where the IRS has not responded by the date it promised or where a delay exceeds 30 days past normal processing time; Form 911 opens one, and a TAS case officer can get a status that the public phone lines cannot. The correspondence guide covers the campus side of the delay.

Questions about Letter 2644C

Have a different notice? The IRS notice decoder lists all 77 in the order they tend to arrive.