IRC §6651 Failure-to-File and Failure-to-Pay: Rate Formulas for Individuals and Businesses

Author: Chenchen Liu, CPA ｜ YCL Tax, Accounting & Advisory

Bottom line

IRC §6651 covers two common “late” penalties: failure to file (FTF) and failure to pay (FTP). On individual and many corporate income-tax paths, FTF is generally about 5% of unpaid tax per month (or part-month), capped at about 25%; FTP is generally about 0.5% of unpaid tax per month, capped at about 25%. If the return is more than 60 days late, a minimum FTF may also apply (lesser of 100% of unpaid tax or the published floor): for returns with due dates in calendar year 2025, that floor is commonly $510; for due dates after December 31, 2025, commonly $525—subject to current IRS published rates/amounts. Partnership Form 1065 / S corporation Form 1120-S use separate per-partner / per-shareholder monthly bases (commonly $245 for CY2025 due dates; $255 for due dates after 12/31/2025, per month for up to about 12 months—subject to current IRS published rates/amounts). For Cary / RTP taxpayers, understanding the formulas helps decode penalty lines on CP14-type notices and evaluate First Time Abate / reasonable-cause options at an educational level. This article is compliance planning only. It does not promise penalty relief or any collection outcome.

Background

The IRS Failure to file penalty and Failure to pay penalty pages, together with Notice 746, summarize published percentages and inflation-adjusted dollar amounts. §6651(a)(1) addresses failure to file a required return on time; §6651(a)(2) addresses failure to pay tax shown on time. When FTF and FTP both apply in the same month, the Code uses a special same-month interaction (high-level: the FTF for that month is generally reduced by the FTP accrued for that month—details in Notice 746 / the statute). Minimum FTF dollars are inflation-adjusted; the IRS publishes different floors by the due-date window.

In practice, Chinese-speaking households along the Cary / Wake / Durham tech corridor often trigger §6651 after assuming Form 4868 extends payment as well as filing, after skipping a non-refund return, or after RSU / cross-border income delays. On the business side, late Form 1120 and per-person bases on late 1065 / 1120-S (in the §6698 / §6699 framework, often discussed with late K-1 packages) can multiply cost quickly. First Time Abate and reasonable cause are publicly described administrative concepts—approval depends on facts and process; this article does not promise an outcome.

What changed / options compared

Note: The comparison below contrasts common misconceptions with compliance framing, not a legislative old-vs-new chart. Rates and dollar floors are subject to current IRS published rates/amounts and the figures on your notice.

1. FTF monthly rate

- Common misconception: One day late equals three months late, or a single flat fee always applies.

- Compliance framing: Generally about 5% per month (including a partial month) of unpaid tax, max about 25%; a minimum FTF may also apply (below). Subject to current IRS published rates/amounts.

2. FTP monthly rate

- Common misconception: FTP uses the same 5% schedule as FTF.

- Compliance framing: Generally about 0.5% per month, max about 25%; about 0.25% during certain approved individual installment periods after a timely filed return; about 1% in certain post–intent-to-levy situations (subject to current IRS published rates/amounts; see Notice 746).

3. Minimum FTF (return >60 days late)

- Common misconception: One outdated fixed dollar always applies.

- Compliance framing: Lesser of 100% of unpaid tax or the published floor. Due dates 01/01/2025–12/31/2025 → commonly $510; due dates after 12/31/2025 → commonly $525. Subject to current IRS published rates/amounts.

4. Extensions (Form 4868 / 7004)

- Common misconception: An extension delays both filing and payment, so FTP cannot start.

- Compliance framing: Extensions generally extend time to file, not time to pay; unpaid tax after the original due date can still accrue FTP (and interest).

5. 1065 / 1120-S per-person monthly base

- Common misconception: A late partnership / S-corp return is one flat fee for the whole entity.

- Compliance framing: Published bases often run per partner / per shareholder per month, up to about 12 months. CY2025 dues commonly $245; after 12/31/2025 commonly $255—subject to current IRS published rates/amounts.

6. First Time Abate / reasonable cause

- Common misconception: “Abatement is automatic” or “being busy is always enough.”

- Compliance framing: FTA and reasonable cause are public educational options that require eligibility and facts. Approval is case-specific; this article does not promise an outcome.

7. Not deposit penalty / TFRP

- Common misconception: Treat §6651 like EFTPS failure-to-deposit or trust-fund recovery.

- Compliance framing: §6651 mainly addresses late return filing and tax payment; deposits are §6656; responsible-person trust fund is §6672—do not mix response scripts.

Self-check: are you affected?

1. Form 1040 / 1120 filed after the statutory (or extended) due date with unpaid tax still outstanding — Match FTF / FTP lines on your notice.

2. You filed 4868 / 7004 but did not pay the balance by the original due date — Check whether FTP and interest have started.

3. Return more than 60 days late — See whether the minimum FTF floor applies for your due-date window (subject to current IRS published rates/amounts).

4. Late Form 1065 or 1120-S with multiple partners / shareholders — Rough-count persons × months using the year’s monthly base (educational only).

5. First-time §6651-type penalty with otherwise clean compliance history — Review public First Time Abate criteria (education—not a promise).

6. Illness, disaster, destroyed records, or similar obstacles — Build a timeline and evidence for a reasonable-cause framing.

7. Cary / RTP bilingual households with possible North Carolina late penalties — Track federal §6651 separately from state assessments.

Simplified example (illustrative only)

Example — Cary household files Form 1040 late

Assume Mr. and Mrs. Zhang still owed about $6,000 of tax on the original due date, and the return was filed and paid a little more than three months late (figures are illustrative only).

- FTF sketch: About 5% × 3 months ≈ 15% × $6,000 → roughly a $900 order of magnitude (before special comparisons); if more than 60 days late, also compare the year’s minimum FTF (e.g., commonly $510 for 2025 due dates; $525 after 12/31/2025) with 100% of unpaid tax—subject to current IRS published rates/amounts.

- FTP sketch: About 0.5% per month on the unpaid balance while it remains unpaid, max about 25%; same-month interaction with FTF follows Notice 746.

- Relief sketch: If First Time Abate public criteria or reasonable-cause facts may apply, review administrative request paths—does not promise approval.

These percentages and dollars do not calculate any real case. Your penalty is the amount on your notice; formula inputs are subject to current IRS published rates/amounts. This article does not promise that relief will succeed.

Action plan and timeline

1. Today: Locate the notice or Online Account lines showing §6651 / failure to file / failure to pay; note tax period, amounts, and assessment date.

2. Check formula inputs: Confirm unpaid-tax base, months late, whether >60 days, and whether an extension covered filing only.

3. Stop the bleeding: File any unfiled returns compliantly; evaluate payment or installment education options for unpaid balances (no approval promise).

4. 1065 / 1120-S: Count partners / shareholders and months late against the year’s monthly base ($245 / $255-type figures subject to current IRS published rates/amounts).

5. Evaluate relief (education): Read IRS public pages on First Time Abate and reasonable cause; assemble compliance history, obstacle facts, and timeline.

6. Respond and document: Follow notice instructions; keep confirmation numbers; file federal and North Carolina items separately.

7. When unsure: Book a YCL Free Consultation with CPA Chenchen Liu and Gloria to decode penalty lines and a compliance document list.

How YCL can help

YCL Tax, Accounting & Advisory (Cary / RTP + Shanghai), with CPA Chenchen Liu and Gloria, supports Chinese-speaking individuals and businesses with bilingual compliance planning:

1. Read §6651 lines — Separate FTF, FTP, minimums, and 1065/1120-S per-person monthly bases.

2. Formula education — Match published rates and dollar floors to tax-year / due-date labels (subject to current IRS published rates/amounts).

3. Extension vs payment calendar — Explain why 4868/7004 extends filing time, not payment due dates.

4. FTA / reasonable-cause framing — When facts support it, help assemble educational materials (no promise of IRS abatement).

5. Tie-in to CP14-type notices — Split tax, penalties, and interest on the account.

6. Two-office support — Cary for U.S. filings and notices; Shanghai for cross-border income and document collection.

7. Free Consultation — Clarify documents and dates—no promised relief or collection result.

FAQ

Q: If I filed an extension, can I still owe failure-to-pay?

A: Generally, an extension mainly extends time to file, not the original payment due date. Unpaid tax after that date can still accrue FTP and interest (subject to current IRS published rates/amounts).

Q: Do FTF and FTP each hit 25% and then simply add?

A: Each has a max of about 25%, but same-month interaction follows special rules (Notice 746 / §6651). Do not replace your notice face amount with a “two times 25%” rule of thumb.

Q: Does First Time Abate always remove the penalty?

A: No. FTA is a public administrative option with eligibility and process requirements; approval is case-specific. This article does not promise an outcome.

Book a consultation

YCL Tax, Accounting & Advisory

Web: yclcpa.com ｜ Email: info@yclcpa.com

Phone: 919-802-8376 / 980-202-0666 ｜ WeChat: YCLUSA

U.S. office: 1140 Kildaire Farm Rd. STE 208, Cary, NC 27511

Shanghai office: 上海佳通路 31 弄中冶祥腾城市广场 2-516

Free Consultation: please bring the penalty notice or Online Account screenshots (you may mask sensitive digits), tax period, proof of filing and payment dates, and any extension form.

Disclaimer

This article is general information only. It is not personalized tax, legal, collection-representation, or investment advice. Penalty rates, minimum dollars, and inflation-adjusted amounts change by tax year and assessment date—verify your letter and current IRS pages. For advice about your situation, consult a licensed professional.