Received an IRS Notice? Your LLC Compliance Checklist Before You Respond

Before you respond to an IRS notice for your LLC, confirm the letter is genuine, find the CP or LTR number, compare the notice with the return it references, and reply by the due date printed on the notice. An IRS notice is not the same as an audit. The IRS sends notices for many reasons, including a balance due, changes to a refund, questions about a return, identity verification, return corrections, and processing delays. For an LLC, the notice is usually due to a discrepancy between what was filed and what the IRS has on file.

The problems begin when owners jump to conclusions and act without reading. They may send money they do not owe or ignore a notice with a deadline. This LLC compliance checklist explains what to verify first and how to respond.

What an IRS Notice Means for Your LLC

An IRS notice means the IRS has a question or has already made a change. Each notice covers a single issue.

The number is important because it tells you what the notice is about. A CP or LTR number is in the upper right corner of the notice. You can also look up the notice by topic on the IRS notice and letter page. A balance due notice calls for a different response than a notice requesting documents.

The notice also names a tax form and a period. Many LLC owners are surprised by this, as the form depends on how the LLC is taxed:

A single-member LLC usually reports on the owner’s personal return.
A multi-member LLC files Form 1065.
An LLC taxed as a corporation files Form 1120 or Form 1120-S.

If the notice names a form you did not expect, this mismatch is your first concern.

LLC Compliance Checklist: Five Steps Before You Respond

Go through each step, in the order provided, before you contact the IRS or send money.

Check the authenticity of the letter. Make sure any link in the notice contains “https” and “irs.gov.” The IRS states that if the letter does not appear in the IRS notice search or looks suspicious, you should call 800-829-1040.
Identify the tax year and the form. Check that the entity name and EIN match your records, and confirm the period corresponds to your records.
Compare the notice to your return. If the IRS made any changes or corrections to your return, compare the notice to the return you filed and keep your comments and notes with your records.
Determine the response date and method. Send your response only to the address on the notice. Send it to a different IRS office only if the notice instructs you to do so.
Gather your evidence. Collect your bank statements, invoices, payroll records, and prior returns for that period.

Treat unsolicited demands about beneficial ownership with extreme caution. According to FinCEN, LLCs, corporations, and other entities formed in the U.S., and their beneficial owners, are exempt from BOI reporting. Entities formed under foreign law and registered to do business in the U.S. are still subject to the requirement. Letters asking a U.S.-formed LLC to file should be confirmed at FinCEN.gov before any action is taken.

LLC Filings That Most Often Trigger Penalty Notices

Late or incomplete entity returns are a common source of penalty notices. The penalty can be assessed even if no tax is owed. The numbers below are for calendar year 2025 returns.

Form	Who files	Original due date	Late-filing penalty
1065	Multi-member LLC taxed as a partnership	March 16, 2026	$255 per partner, per month, up to 12 months
1120-S	LLC taxed as an S corporation	March 16, 2026	$255 per shareholder, per month, up to 12 months
1120	LLC taxed as a C corporation	April 15, 2026	5% of unpaid tax per month, up to 25%

The $255 penalty applies to returns due after December 31, 2025. It is calculated for each partner or shareholder for every month the return is late. For example, a two-member LLC that files its return four months late can owe $2,040 (2 x $255 x 4) even if no tax is due.

Extensions change the picture:

Form 7004 gives an automatic six-month extension.
The extended deadline for Forms 1065 and 1120-S is September 15.
The extended deadline for Form 1120 is October 15.

If you are a C corporation or LLC, you can file your return as late as October 15 with an extension. Foreign-owned LLCs face a separate penalty. A single-member LLC owned by a non-U.S. person generally must file Form 5472 with a pro forma Form 1120, and the penalty for failing to file is $25,000. Confirm the rules on IRS.gov, because this filing is easy to miss when no income tax is due.

How to Respond: Pay, Dispute, or Ask for More Time

Your response depends on whether you agree with the notice.

You agree and owe money: Pay by the due date. If you cannot pay the full amount, the IRS asks you to pay as much as you can.
You agree and owe nothing: Generally, no reply is needed. Reply only if the notice asks you to.
If you disagree, explain your rationale in writing and attach supporting documents. Refer to the instructions on the notice for your appeal rights. The IRS suggests allowing at least 30 days for a response.
You need more time: Contact the IRS before the due date passes.

Sixty days is a common window for return processing issues. However, the date listed on the letter controls.

For complex notices, a CPA, enrolled agent, or attorney can act on your behalf with a signed Form 2848 (Power of Attorney).

Why Your Records Decide the Outcome

The quality of your records usually determines the outcome of a notice. The IRS reviews records to decide whether there is a discrepancy and, if so, how large it is. If the IRS identifies underreported income and your records do not reconcile invoices to deposits, you are arguing from memory.

Mixed personal and business expenses make this worse because every unaccounted-for transaction becomes an unwanted question. Keeping a separate business account and categorizing expenses on time helps. The cost of preparing your records on time is far less than the cost of reconstructing a year’s worth of transactions, and professional bookkeeping and tax-filing support can keep those records ready before a notice ever arrives.

State Notices Are Not IRS Notices

The IRS addresses only federal taxes. State Departments of Revenue and Secretary of State offices issue their own notices.

Annual reports and franchise taxes are state-specific. California charges LLCs a minimum franchise tax of $800, while other states charge less. Check your state agency’s website for more information.

State mail is often delivered to your registered agent. If the registered agent information is out of date, notices can pile up, and penalties can build while the LLC falls out of good standing. Keep your registered agent information up to date.

IRS Notice Response Checklist

Locate the notice number, tax year, and form.
Verify the notice on IRS.gov using the notice number.
Check the notice against your filed return and business records.
Mark the due date of your response.
Choose your response method.
Decide whether you agree, disagree, or need more time.
Gather your records and documents, and send copies of everything.
Check whether there are related state filings you need to complete.

Common Mistakes Made When Responding to an IRS Notice

Paying a penalty without first requesting relief for reasonable cause.
Sending a response to the wrong agency.
Using an old mailing address.
Thinking no tax means no filing.
Missing a response date, which could cost you your right to appeal and may result in additional interest and penalties.

The Takeaway: Verify First, Then Respond by the Deadline

Treat the notice as something to verify rather than something requiring an immediate reaction. Check that it is authentic. If it is, match it to your return and respond by the due date. If your LLC has filings that were never completed, file those first, because getting a penalty lifted while the return is still missing is very difficult.

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