Who has to pay quarterly?
Generally, you need to make estimated payments if you expect to owe $1,000 or more for 2026 after withholding and credits. Freelancers, 1099 contractors, gig workers and people with a side business usually do, because nobody withholds tax from their pay.
The safe harbor: how to avoid the penalty
You won't owe an underpayment penalty if your withholding plus on-time estimated payments add up to at least the smaller of these:
- 90% of your 2026 tax, or
- 100% of your 2025 tax (110% if your 2025 AGI was over $150,000, or $75,000 if married filing separately). This only applies if your 2025 return covered a full 12 months.
The prior-year option is the predictable one. If you earn more this year, you can pay based on last year's tax, avoid the penalty, and settle the rest in April. Just set that money aside.
The quarters aren't really quarters
The IRS periods are uneven. Q1 covers January-March, Q2 only April-May, Q3 June-August and Q4 September-December. That's why the June payment often catches people out. If you also have a W-2 job, you can skip estimates entirely by raising the withholding on your W-4. Withholding counts as if it were paid evenly through the year, even when it starts late.
Missed a payment?
Pay as soon as you can. The penalty works like interest, charged for each day a payment is late. It isn't a flat fine, so a late payment still costs much less than skipping it. For Q4 2026, you can skip the January 15, 2027 payment if you file your 2026 return and pay the full balance by February 1, 2027.