Who owes quarterly
If you expect to owe $1,000 or more in total federal tax (income + SE) after withholding and credits, the IRS wants quarterly payments. Most self-employed people cross that threshold the first quarter they have real income.
The 2025 deadlines
| Quarter | Period covered | Due date |
|---|---|---|
| Q1 | Jan 1 – Mar 31 | April 15 |
| Q2 | Apr 1 – May 31 | June 17 (normally June 15) |
| Q3 | Jun 1 – Aug 31 | September 16 |
| Q4 | Sep 1 – Dec 31 | January 15, 2026 |
Notice Q1 is the shortest (3 months) and Q3 is 3 months of the year with a mid-month deadline. This is an IRS quirk — periods aren't equal.
The safe harbor in one sentence
If you pay (through quarterly estimates + withholding) at least 100% of last year's total tax (or 110% if last year's AGI was over $150k), you owe no underpayment penalty — regardless of what you actually owe this year.
Why this is the move for most self-employed people
Projecting current-year income is hard, especially in a business with uneven revenue. But you know last year's tax exactly — it's on line 24 of your prior-year Form 1040. Divide by 4. Pay that each quarter. You're safe.
Even if your income triples this year, you won't owe the underpayment penalty as long as you met the 100%/110% prior-year target. You'll owe the big balance in April, but no penalty.
The alternative: 90% of current year
If you're having a dramatically worse year and want to pay less now, the other safe harbor is to pay 90% of what you'll actually owe this year. Works fine if you can project accurately. Risky if you can't.
Safe harbor numbers for income levels
| Last year's total tax | Last year's AGI | Required annual payment | Per quarter |
|---|---|---|---|
| $8,000 | $80,000 | $8,000 (100%) | $2,000 |
| $22,000 | $140,000 | $22,000 (100%) | $5,500 |
| $35,000 | $180,000 | $38,500 (110%) | $9,625 |
| $60,000 | $280,000 | $66,000 (110%) | $16,500 |
How to pay
- IRS Direct Pay (directpay.irs.gov) — free, from bank account
- EFTPS (eftps.gov) — free, requires enrollment (takes 5–7 days)
- Credit card — ~1.8% processing fee, but earns rewards if the card's reward rate exceeds the fee
- Form 1040-ES + check — mail with a voucher; old-school but works
W-2 withholding: the hidden lever
Withholding (from a W-2, spouse's W-2, or pension) is treated by the IRS as paid evenly throughout the year, regardless of when it actually happened. Quarterly estimates are treated as paid on the date paid.
If you missed Q1 and Q2 estimates, you can catch up by massively over-withholding on your spouse's W-2 for the rest of the year. That over-withholding gets spread back to Q1 and Q2 retroactively, often avoiding the penalty entirely.
State quarterly estimates
Most states with income tax also require quarterly estimates. Due dates often align with federal but not always. Rules vary. If you owe state tax on self-employment income, check your state's department of revenue.
The simple routine
- After filing last year's return, calculate the safe harbor number (100% or 110% of total tax from Form 1040 Line 24)
- Divide by 4
- Set a calendar reminder for April 15, June 15, September 15, January 15
- Pay the same amount each quarter via Direct Pay
- Done. No penalty regardless of current-year income.
We calculate your safe harbor automatically.
Upload last year's return. We show you exactly what each quarterly payment should be.