--- title: 7 Tax Deadlines Business Owners Need to Track date: '2025-11-14T08:00Z' updated: '2026-07-29T00:00:00Z' reviewed: '2026-07-09' reviewed_by: mia-anne-pham-reeves-cpa author: 'Mia Anne Pham Reeves, CPA' description: >- Track seven IRS deadlines business owners should know, plus quarterly estimate habits that reduce surprises and penalty risk. tags: - tax deadlines - estimated taxes - safe harbor - extensions - 1099-NEC - W-2 - S Corp - partnership - compliance - calculator sources: - >- IRS Publication 505 - Tax Withholding and Estimated Tax: https://www.irs.gov/forms-pubs/about-publication-505 - 'IRS Direct Pay help: https://www.irs.gov/payments/direct-pay-help' - >- IRS EFTPS: https://www.irs.gov/payments/eftps-the-electronic-federal-tax-payment-system - >- IRS information return penalty procedures: https://www.irs.gov/irm/part21/irm_21-003-011 canonical: >- https://www.havenstoneadvisory.com/resources/blog/tax-landmines-7-dates-keep-you-out-of-trouble --- > Three penalties. One missed date. > Here are the **seven deadlines** that keep your money, and your sanity. Plus, two simple ways to set **quarterly estimates** so you never guess again. > **Note:** Extensions extend **filing**, not **paying**. # The quick take Most IRS pain comes from **missed dates**, not bad math. **System = calendar + current books + consistent estimates.** Lock in the seven dates, pick one estimate method, and pay by the **original** due dates. --- # The fast map (all dates at a glance) **Jan 31**: W‑2s & 1099‑NEC to workers **and** filed (SSA/IRS). **Mar 15**: **S Corp (1120‑S)** & **Partnership (1065)** returns due (or extend). **Apr 15**: **Individual 1040 due** + **Q1 estimates**. **Calendar‑year C Corps (1120)** also file now. **Jun 15**: **Q2 estimates due**. **Sep 15**: **Q3 estimates due** + **S Corp/Partnership final** (if extended). **Oct 15**: **Individual final** (if extended). **Dec 31**: **Last day for most year‑end strategies** (comp, assets, reimbursements). **Jan 15 (next year)**: **Q4 estimates due** (note: **Jan 15**, not Jan 31). Prefer a one‑page checklist? Open our **[Tax Playbook & Estimator](/resources/guides/tax-playbook)** for all dates at a glance and a built‑in estimator. --- # What “extension” really means Extensions give you more time to **file**, not more time to **pay**. If you don’t pay enough by the original due date, you’ll rack up **failure‑to‑pay** and **interest**. > **Bottom line:** Pay by the original date. File later if you must. --- # Quarterly estimates: two ways to set them Pick one method and stay consistent: ## Method 1: Prior‑Year Safe Harbor (easy mode) - Pay **100%** of last year’s total tax (**110%** if prior‑year AGI > **$150k MFJ** / **$75k MFS**). These safe-harbor percentages are in [IRS Publication 505](https://www.irs.gov/forms-pubs/about-publication-505). - Divide into four equal payments due **Apr 15, Jun 15, Sep 15, Jan 15**. **Use when:** income is steady and you want a simple penalty shield. ## Method 2: Rolling P&L (precision mode) - Use **year‑to‑date profit** each quarter to compute what you actually owe. - Requires books **closed by the 15th** monthly. **Use when:** income swings (seasonal/project‑based) and your books are disciplined. **How to pay:** IRS **[Direct Pay](https://www.irs.gov/payments/direct-pay-help)** or **[EFTPS](https://www.irs.gov/payments/eftps-the-electronic-federal-tax-payment-system)** (save confirmations). States have their own portals/dates, set those too. **Tool:** Compare methods and auto‑compute targets in our **[Tax Playbook & Estimator](/resources/guides/tax-playbook)**. --- # Date #1–#2: **Jan 31** & **Mar 15** **Jan 31 - W‑2s & 1099‑NEC** Send W‑2s to employees and 1099‑NEC to contractors **and** file with SSA/IRS. Late or missing information returns carry their own penalties ([IRS penalty procedures](https://www.irs.gov/irm/part21/irm_21-003-011)). **Prevent notices:** Clean your vendor list by **Dec 15** and collect **W‑9s** before you pay vendors. **Mar 15 - S Corp (1120‑S) & Partnership (1065)** File the return **or** file an extension. If you extend, **pay what you expect to owe now** to avoid failure‑to‑pay and interest. --- # Date #3: **Apr 15** (+ C Corp note) **Apr 15 - Individual returns due + Q1 estimates.** **Calendar‑year C Corps** also file **Form 1120** now. If you extend, **send payment with the extension** to limit interest. --- # Dates #4–#6: **Jun 15, Sep 15, Oct 15** - **Jun 15 - Q2 estimates** - **Sep 15 - Q3 estimates** **+** S Corp/Partnership **final** if extended - **Oct 15 - Individual returns final** if extended Tip: Put calendar reminders at **30 / 14 / 7 days** ahead of each date. --- # Date #7: **Dec 31 - Strategy deadline** This is where strategy either lives or dies: - **Owner payroll (S Corp reasonable comp)** set before year‑end - **Fixed‑asset buys & bonus depreciation** timing - **Retirement plan setup** (adoption vs. funding deadlines vary) - **Accountable reimbursements** (home office, mileage, phone) recorded **this year** After Dec 31, many levers are gone until next year. --- # Your simple system Make this **boring and automatic**: 1. **Calendar** these seven dates (plus **Jan 15**) with reminders **30/14/7 days** out. 2. **Close books monthly** by the 15th. 3. Pick **Safe Harbor** _or_ **Rolling P&L**. Don’t switch mid‑year. 4. Pay via **Direct Pay/EFTPS** and save confirmations. 5. **Bookmark:** **[Tax Playbook & Estimator](/resources/guides/tax-playbook)** for deadlines + calculator. --- # Quick wins you can do today - **Lock the dates** on your calendar (federal + your state). - **Pre‑flight Jan 31:** vendor W‑9s, worker statuses, addresses, and e‑file setup. - **Choose your method:** Safe Harbor vs. Rolling P&L; schedule the next payment. - **Reserve cash:** earmark funds for Q1/Q2 estimates now. --- # How HavenStone helps Our process for busy owners: 1. **Calendar & cadence:** We load the seven dates, reminders, and a monthly close rhythm. 2. **Entity & workflow audit:** Extensions, estimate method, vendor/worker files. 3. **Implementation:** Estimate calculator (Safe Harbor vs. Rolling P&L), payment workflows (Direct Pay/EFTPS), and extension‑with‑payment playbooks. 4. **Monitoring:** Quarter‑by‑quarter variance checks so you stay penalty‑proof. You’ll know **what to do, why it matters, and the dollar impact.** --- # Common questions **How do I decide between Safe Harbor and Rolling P&L?** If your income swings, Rolling P&L can reduce overpaying, but only if books are current. If you want **simple** penalty protection, Safe Harbor works. **Is Jan 15 the last estimate, not Jan 31?** Correct - **Q4 is due Jan 15 (next year)** for most individuals (moves to the next business day if it lands on a weekend/holiday). **We’re an S Corp on extension, what’s the real risk?** Extensions are fine, but **pay by Mar 15** (calendar‑year) to avoid failure‑to‑pay and interest. File by the extended September deadline. **Where can I see all dates and calculate estimates?** Use our **[Tax Playbook & Estimator](/resources/guides/tax-playbook)** for a one‑page deadline map and a quick calculator. --- # What to do next **Simple start:** Put the seven dates (plus **Jan 15**) on your calendar and pick your estimate method today. **Grab the tools:** Open the **[Tax Playbook & Estimator](/resources/guides/tax-playbook)** to view deadlines and calculate your quarterly targets (Safe Harbor vs. Rolling P&L). **Full service:** [Schedule a strategy session](https://www.havenstoneadvisory.com/schedule-consultation) with HavenStone. We’ll map your deadlines, set your estimate method, and build a no‑drama payment system you can run in 15 minutes a quarter.