IRS Letter 2645C

If you own a Wyoming LLC as a non-resident and a windowed envelope from the Internal Revenue Service lands in your mailbox (or your registered agent forwards a scan), the first reaction is almost always alarm. For most non-resident founders, the very first IRS letter they ever receive is Letter 2645C, and it arrives at the worst possible psychological moment: a few weeks after they have mailed or faxed something important, such as Form 5472 with a pro forma 1120, an EIN application, or a reply to a prior notice. The good news is that Letter 2645C is, in the overwhelming majority of cases, the least threatening piece of correspondence the IRS produces. It is a holding letter. It says, in bureaucratic language, "we have your stuff, we are working on it, please be patient." This page explains exactly what the letter is, why the IRS sends it, how to read it line by line, what to do and what not to do, and the handful of situations where it deserves closer attention.

What Letter 2645C actually is

Letter 2645C is an interim or "holding" letter. The IRS issues it when a unit inside the agency has received correspondence from you (or from someone acting on your behalf, such as a tax professional with a power of attorney on file) but cannot finish processing it within the agency's normal response window. Rather than leave you in silence, the IRS sends 2645C to acknowledge receipt and buy itself more time. It is generated and mailed by an IRS function, not by a specific human auditor reviewing your case in detail, which is why the language feels generic.

The single most important thing to understand is that 2645C does not assert that you owe money, does not propose a change to a return, does not announce an audit, and does not impose a penalty. It contains no figures to dispute and no box to check. It is purely informational. The IRS is essentially saying that your matter is in a queue and they expect to need additional time, commonly stated as 60 days, and sometimes longer depending on the function involved and the workload at the time.

For non-resident LLC owners specifically, the most frequent trigger is the annual Form 5472 plus pro forma 1120 filing that every foreign-owned single-member disregarded entity must submit. These returns are processed by hand at a specific IRS campus, often run behind, and routinely generate a 2645C acknowledgment. Receiving one after you mail your 5472 is so common that it should be treated as part of the normal rhythm of compliance rather than as a red flag.

Why the IRS sends a holding letter at all

The IRS operates under internal timeliness standards. When a taxpayer writes in, responds to a notice, or files a return that must be reviewed manually, the relevant unit is expected to act within a set number of days. When the unit cannot meet that standard, because of volume, staffing, or the complexity of the item, it issues an interim letter to keep the taxpayer informed and to document that the agency has not abandoned the file. Letter 2645C is one of those interim letters, and Letter 2644C is a closely related variant used in similar circumstances.

This matters for non-residents because the functions that handle international filings, paper-filed returns, and EIN-related correspondence are among the slowest in the entire agency. A pro forma 1120 with a 5472 attached is a paper document that a person physically opens, sorts, and keys. That work happens at scale, and during peak periods it backs up. The 2645C is the IRS telling you that your paper is in the building and in line, not lost.

Understanding the "why" should reduce anxiety. The letter is a sign of a functioning, if slow, process. The far worse outcome would be no acknowledgment at all, followed months later by a penalty notice claiming you never filed. A 2645C is contemporaneous evidence that the IRS received your correspondence, and you should preserve it precisely for that reason.

How to read your 2645C line by line

Although the letters look generic, each one contains specific details that you should locate and note. Read the whole page rather than skimming the headline. The key elements to find are described in the table below.

Pay particular attention to the sentence that identifies what the IRS is responding to. Sometimes it names the form or notice; sometimes it is vague and merely says "your correspondence." If it is vague, use the date of the letter to reason backward to whatever you most recently sent. If you mailed your 5472 in March and the 2645C is dated in May, the connection is almost certainly that filing.

Also note whether the letter mentions a specific tax period or tax year. For an annual 5472 filing, the period referenced should match the year of the return you submitted. A mismatch is worth a closer look, because it could mean the letter relates to a different item than you assumed.

What to do, step by step

For the typical non-resident founder who has just filed a 5472 or responded to a routine notice, the correct response to a 2645C is calm, minimal, and documented. The letter asks nothing of you, so the work is about record-keeping and patience rather than action.

1. Save the original letter and a scanned copy. Store the scan with your tax records for that year, alongside proof of what you sent (fax confirmation, certified-mail receipt, or courier tracking).
2. Identify which correspondence the letter acknowledges, using the date and any form or period reference, and write a one-line note to yourself linking the 2645C to that filing.
3. Record the reference or control number and the IRS contact number in the same place. You will want both if you ever need to call.
4. Calendar the end of the stated window. If the letter says 60 days, set a reminder for roughly 75 days out to allow for mailing time.
5. Do nothing else until that date. Specifically, do not refile, do not call immediately, and do not send a follow-up letter "just to be safe."
6. If the window passes with no substantive response, call the IRS number on the letter, quote the reference number, and ask for the status of the matter.

If you are a customer of a formation or compliance service, forwarding a copy of the letter to your provider is a sensible step so they can confirm your read of it and flag anything unusual. A second set of eyes costs nothing and occasionally catches a detail, such as a wrong tax period, that changes the interpretation.

What not to do

The mistakes non-residents make with 2645C are almost always overreactions, and several of them actively cause harm. The most damaging is refiling the same return. If you mailed a 5472 and then, worried it was lost, mail a second copy after receiving the 2645C, you create a duplicate that the IRS now has to reconcile. Duplicate processing can slow your case further and, in some cases, generate confusing follow-up correspondence. The 2645C is itself proof the original was received, so refiling is unnecessary and counterproductive.

A second mistake is calling the IRS on the day the letter arrives. Phone agents can rarely accelerate manual processing, and calling before the stated window has elapsed wastes long hold times to be told to keep waiting. The number on the letter is for use after the window passes, not before.

A third mistake is ignoring the letter entirely and throwing it away. While 2645C requires no reply, it is valuable evidence. If a penalty notice ever appears claiming you filed late or not at all, the 2645C and your mailing proof together demonstrate that the IRS had your correspondence on a specific date. Discarding it removes a useful piece of your defense.

Finally, do not treat a 2645C as permission to stop other compliance. It acknowledges one item; it does not extend deadlines for anything else. Your registered agent still must be maintained, your annual report and license tax in Wyoming are still due on their own schedule, and next year's 5472 is still due on its own date regardless of where this year's processing stands.

A worked example: the 5472 timeline

Consider a concrete sequence that many non-resident, single-member LLC owners will recognize. A founder forms her Wyoming LLC, obtains an EIN, and operates a software business serving customers entirely outside the United States. Because her LLC is foreign-owned and disregarded, she must file Form 5472 with a pro forma 1120 each year, due April 15, and she chooses to fax and mail it in mid-March to be safe.

In early May, roughly seven weeks later, a Letter 2645C arrives. It is dated in late April, references her LLC's EIN, says the IRS received her correspondence, and states it needs up to 60 days to respond. She does not panic. She recognizes this as the routine acknowledgment of her 5472 filing. She saves the letter, links it in her records to her March fax confirmation, records the reference number, and calendars a reminder for mid-July, about 75 days from the letter's date.

July arrives with no further letter. Rather than assume the worst, she understands that "no news" after an interim letter often simply means the filing was accepted and closed without any further correspondence; the IRS does not always send a separate "all done" letter for a clean 5472. She calls the number on the 2645C once, quotes her reference number, and confirms the return was processed and no further action is required. Total work on her part across four months: file once, save one letter, set one reminder, make one short call. No penalty, no audit, no refiling.

When 2645C does deserve closer attention

While the letter is benign on its own, the context around it occasionally matters. The 2645C should be read together with anything else that arrived around the same time. If you received a substantive notice alongside or shortly before the holding letter, the substantive notice is the one that governs your deadlines and required actions.

• If a CP-series notice such as a CP2000 arrived, that notice proposes specific changes and has a hard response deadline. The 2645C does not pause that deadline; act on the CP notice on its own timeline.
• If you previously received a penalty notice, for example for a late or missing 5472, and you responded in writing, a subsequent 2645C means the IRS is reviewing your response. That is normal, but the underlying penalty matter is still live until you receive a substantive resolution.
• If the 2645C followed a request that involved money, such as a refund claim or an installment arrangement, expect that the money side of the matter may be delayed while processing continues.
• If the letter references a tax period or form you do not recognize, treat that as a genuine flag. It could indicate a misapplied identifier, identity confusion, or correspondence about something you did not send. In that case, calling to clarify sooner rather than later is justified.

The guiding principle is that 2645C never increases your obligations, but it also never erases obligations created by other notices. Sort your mail by what each piece demands: an interim letter demands patience, an action notice demands a timely, written response.

How to tell a holding letter from an action letter

Non-residents who are new to the US tax system benefit from a simple mental taxonomy of IRS mail. Most correspondence falls into one of three buckets, and knowing which bucket a letter belongs to tells you how urgently to respond.

The first bucket is interim or holding letters, of which 2645C and 2644C are the common examples. These say the IRS received something and needs more time. They contain no dollar amounts to dispute and no required reply. The correct response is to file the letter and wait.

The second bucket is action notices, typically in the CP series. A CP2000, for instance, proposes adjustments to income or tax and gives you a specific number of days to agree or disagree. These letters contain figures and deadlines. They require a timely, documented response, and missing the deadline can turn a proposal into an assessment.

The third bucket is penalty and assessment notices. For non-resident LLC owners the most relevant is a penalty assessed for a late, incomplete, or unfiled Form 5472, which under the relevant statute carries a substantial penalty per failure. These notices state an amount and explain how to request abatement or otherwise dispute it. They demand prompt, written attention, usually with a reasonable-cause explanation if you are seeking relief. When you cannot tell which bucket a letter belongs to, match the letter or notice code against the IRS's published description of that code and keep every page of the document.

Record-keeping that protects you

Because the IRS communicates almost entirely by mail and processes international filings slowly, your own records are your best protection. Treat every piece of IRS correspondence, including benign holding letters, as part of a permanent compliance file organized by tax year. For each year, keep proof of what you sent and when, plus every letter you received in response.

A practical filing system for a non-resident LLC owner looks like this. For each tax year, keep the as-filed copy of your 5472 and pro forma 1120, the fax confirmation page or certified-mail and courier tracking, and then, in date order, every IRS letter that followed, including any 2645C. Note on each letter which earlier item it relates to. This chain lets you reconstruct, months or years later, exactly what happened and prove it if a question ever arises.

The reason this matters is concrete. The penalty for failing to file a complete and timely 5472 is large, and disputes over whether and when a return was filed are won or lost on documentation. A 2645C dated weeks after your mailing, paired with your mailing proof, is strong evidence that the IRS had your return in hand. Keeping it is cheap insurance against an expensive argument.

Common questions and edge cases

A few recurring situations confuse non-resident founders. One is receiving more than one 2645C for what seems like the same matter. This can happen when processing drags on and the IRS issues a second interim letter as another internal window lapses. Multiple holding letters are not cumulative bad news; they simply mean the item is still in process. Continue to wait, and use the date of the most recent letter to reset your follow-up reminder.

Another edge case is a 2645C that arrives when you do not recall sending anything recently. Work backward methodically. Did your tax professional or registered agent correspond with the IRS on your behalf? Did you file an EIN application or a prior-year return that is only now being processed? International and paper processing can lag by many months, so a letter can reference correspondence you sent long ago. If you genuinely cannot connect the letter to anything you or your representatives sent, and especially if it cites an unfamiliar tax period, call the number on the letter to confirm it relates to your account and not to a mix-up.

A third scenario involves timing around extensions. If you extended your filing with Form 7004 and then filed later in the year, expect the acknowledgment cycle, including any 2645C, to run later as well. The interim letter's clock is tied to when the IRS received your correspondence, not to the original April due date, so do not be alarmed if your holding letter arrives in the summer or autumn after an extended filing.

If your Wyoming LLC is not yet formed and you want a clean, well-documented compliance trail from day one, you can form a Wyoming LLC through us for $397 all-inclusive, with the LLC typically formed in about 24 hours and an EIN obtained without an SSN, so your first 5472 and any holding letters that follow land against a properly set-up entity with a registered agent already in place.