IRS Letters & Payroll Tax

Letter 3164: The IRS TFRP Investigation Contact Letter, Explained (2025)

By Angeline Balsitis, EA · Reviewed by Melissa Ly, Chief Tax Officer · Updated June 28, 2026 · Editorial Standards

Why you got Letter 3164

Somewhere behind this letter is a business that fell behind on payroll taxes. When an employer withholds income tax and the employees' share of Social Security and Medicare from paychecks, that money is held "in trust" for the government. If the business doesn't pay it over, the IRS can come after the people who were responsible — personally.

Letter 3164 is how a revenue officer tells you they may reach out to other people while building that case. Under the law (Internal Revenue Code section 7602(c)), the IRS has to give advance notice before contacting third parties about your tax matter. This letter is that notice. The IRS explains the penalty itself on its Trust Fund Recovery Penalty page.

So getting Letter 3164 usually means two things at once: the IRS is looking at unpaid payroll taxes, and your name is on the list of people it wants to investigate as a "responsible person."

What happens if you ignore it

The TFRP process moves in stages. Each one narrows your options and raises the stakes. Ignoring Letter 3164 doesn't slow it down — it just means the case gets built without your side of the story:

1. Letter 3164 — third-party contact notice. The investigation has started. No assessment yet. You are here.
2. Form 4180 interview — the revenue officer questions you (and others) to decide if you were "responsible" and acted "willfully." Your answers become evidence.
3. Letter 1153 & Form 2751 — the IRS formally proposes the penalty against you and gives you 60 days to agree or appeal.
4. Assessment — if you don't respond, the penalty becomes your personal debt. Standard collection follows: federal tax liens, bank levies, and wage garnishments — against you, individually, not just the business.

The hard part of the Trust Fund Recovery Penalty is that it survives almost everything. The business can close, file bankruptcy, or disappear — and the IRS can still collect the trust fund piece from the people it names. That's why the early stage you're in right now is the best time to act.

Who the IRS can hold responsible

The TFRP can apply to more than just the owner. The IRS looks for anyone who had the duty to collect or pay over the taxes and willfully failed to do it. That can include:

• Owners, officers, partners, and members of an LLC
• Bookkeepers and payroll managers who decided which bills got paid
• People with check-signing authority or control over the bank account
• Sometimes outside accountants or family members, if they made the financial calls

"Willful" doesn't mean evil intent. It usually means you knew the taxes were due and chose to pay other bills — rent, suppliers, payroll — first. More than one person can be held liable for the same debt, and the IRS often pursues several people at once. Our deeper guide on the Trust Fund Recovery Penalty and who is personally liable walks through both tests in plain English.

How much is at stake

The TFRP equals 100% of the trust fund portion of the unpaid payroll taxes. Here's a simple worked example:

• A business owes $80,000 in unpaid Form 941 payroll taxes for several quarters.
• Of that, roughly $50,000 is the trust fund portion — income tax withheld plus the employees' half of Social Security and Medicare.
• The remaining ~$30,000 (the employer's matching share, plus penalties and interest) stays with the business.
• The IRS can assess that $50,000 personally against each responsible person it identifies.

The penalty does not include the employer's share or business-level penalties — but $50,000 following you home is still life-changing. If the underlying business debt is itself a problem, our guide to 941 back taxes when a business falls behind on payroll taxes explains how the business and personal sides connect.

Your options after Letter 3164

You have more control at this stage than later. Depending on your situation, you may be able to:

• Show you weren't a responsible person. If you had no real authority over the money — no check signing, no decisions about which bills got paid — that's a defense worth documenting now.
• Show you didn't act willfully. If you genuinely didn't know about the unpaid taxes, or were misled, that matters.
• Challenge the numbers. The trust fund figure the revenue officer is working from isn't always right.
• Resolve the underlying balance. If the business can pay or set up an agreement, that can shrink or end the personal exposure.
• Prepare for the interview. The Form 4180 questions are predictable. Knowing how your answers will be read is half the battle.

One thing to be clear-eyed about: nobody can promise the penalty goes away. Anyone guaranteeing they'll make a TFRP disappear before reviewing the facts is selling you something. The honest goal is to put the strongest, best-documented version of your case in front of the IRS before it's locked in.

How to respond to Letter 3164, step by step

1. Don't panic, and don't ignore it. This is the investigation stage — you still have options and rights. But the clock is running.
2. Read it carefully. Note the revenue officer's name, the tax periods involved, and any response date or interview request.
3. Gather your records. Pull bank signature cards, payroll records, corporate minutes, and anything showing who actually controlled the money during the unpaid quarters.
4. Decide on representation before the interview. The Form 4180 interview is the heart of the case. You can authorize an experienced tax professional to handle it using Form 2848 power of attorney, so you're not answering on the spot.
5. Verify it's really the IRS. A real revenue officer carries two forms of ID (a pocket commission and an HSPD-12 card). Payments never go to gift cards or wire transfers — only to the U.S. Treasury. The IRS describes the rules on its third-party contact page.
6. Watch for Letter 1153. If the penalty is proposed, you generally have just 60 days to appeal. Our guide to Letter 1153 and the 60-day deadline covers exactly how to protest.

Letter 3164 questions, answered

This guide is general information, not tax or legal advice for your specific situation. Eligibility for IRS programs depends on individual facts and circumstances; no outcome is guaranteed.

Related guides: Letter 3172 — Notice of Federal Tax Lien: What It Means, Your Deadline, and What to Do · Letter 525 IRS: The Audit Report and 30-Day Letter, Explained · Letter 531 Notice of Deficiency: What It Means, Your Deadline, and What to Do · IRS Letter 692: How to Appeal Audit Results · Letter 725-B: IRS Revenue Officer Visit — What It Means and What to Do