The quarterly tax checklist for small operations
Quarterly taxes fail small businesses for one reason: nobody puts the dates on the calendar, so April and June become emergencies. This is the checklist — the four payment windows, what counts as deductible, and the records that make filing boring instead of terrifying. (Educational only: we are not tax advisors, and your accountant's answer beats any article.)
Editorial independence & scope. JK23 LLC publishes independent financial education. We are not a bank, broker, investment adviser, or insurance company. Nothing on this site is personalized financial, investment, legal, or tax advice, and nothing here is an offer or solicitation of any financial product. Capital is at risk in any market. Consult a licensed professional about your situation.
The four dates (they move to the next business day if they land on a weekend):
| Quarter covers | Payment due | Note |
|---|---|---|
| Jan 1 – Mar 31 | April 15 | Same day as the annual return for individuals |
| Apr 1 – May 31 | June 16 | The short, easy-to-miss quarter |
| Jun 1 – Aug 31 | September 15 | Summer is over, so is the grace |
| Sep 1 – Dec 31 | January 15 (next year) | Catch-up before the cycle restarts |
In the US, paying at least 100% of last year's total tax (110% if your income is over a threshold) across your four estimates generally protects you from underpayment penalties — even if this year turns out bigger. Check current numbers with a professional; the principle is what to remember.
How much to pay each quarter
Two honest methods. Last year's safe harbor (simple, protected, may overpay) or this year's running profit × your tax rate (accurate, requires you to know your profit — which the bookkeeping lesson makes possible). Many owners use last year's numbers for Q1–Q2, then true-up with real profit in Q3–Q4.
- Sole prop / single-member LLC: business profit lands on your personal return — estimate on the combined income.
- S-corp / C-corp owners: salary withholding + the entity's own estimates — your CPA sets the split.
- State income tax is a separate estimate in most states — the federal dates usually match, but confirm yours.
Deductions: the honest short list
A deduction is a real, ordinary, necessary business expense with a record — not a loophole. The common safe categories:
- Home office: the actual-expense or simplified-per-square-foot method — dedicated space, honestly measured.
- Vehicle: actual costs with a mileage log, or the standard mileage rate.
- Equipment & software, insurance premiums, professional fees (yes, your bookkeeper and CPA), advertising, business travel and meals (rules differ — meals are usually partial).
- Health insurance premiums for self-employed owners: generally deductible above the line.
Disallowed deductions usually share one shape: personal expenses wearing a business costume — the family trip 'to visit a client,' the truck that never hauls anything. Keep the business purpose visible in the record and the problem never starts.
The 10-minute quarterly ritual
- Week before each due date: pull the quarter's profit from your bookkeeping tool.
- Pay the estimate (IRS Direct Pay online takes five minutes, state portal similar).
- Save the confirmation to your tax records folder — you'll need them at filing.
- January: hand your CPA clean books and the four confirmations; filing becomes translation, not reconstruction.
Frequently asked questions
What if I miss a quarterly payment?
Pay as soon as you realize — the penalty accrues, it doesn't compound catastrophically. The real cost of a missed quarter is usually the interest-rate-sized penalty plus the stress; the safe-harbor rule then protects the rest of the year if your earlier payments were on track.
Do I really owe estimates my first year?
If the business earns, yes — but the safe harbor for a first year with no prior obligation is what protects most people. This is precisely the question to ask a CPA in your first month of business, not your first April.
Are these dates the same in every state?
Federal dates are fixed; state estimate dates mostly mirror them, but a few states differ. Your state's tax authority site lists them, and any tax software will hold your hand through it.