What happens if I miss a quarterly payment?

You may owe an underpayment penalty for that period, calculated as interest on the shortfall from the due date until paid. A larger later payment doesn't erase an earlier underpayment, because the penalty is computed quarter by quarter — pay as soon as possible to limit it.

Can I just pay everything in April instead?

Not without penalty. The system is pay-as-you-go and the penalty is assessed per period, so paying the full year's tax in April leaves the earlier quarters underpaid — even if the annual total is correct.

How do I avoid the penalty if my income is unpredictable?

Use the prior-year safe harbor: pay 100% (or 110% if your prior-year AGI exceeded $150,000) of last year's total tax in four equal installments. This protects you from the penalty regardless of how much your income rises this year.

How do I actually pay my quarterly estimates?

The fastest, free options are IRS Direct Pay from a bank account and the Electronic Federal Tax Payment System (EFTPS); you can also pay by card for a processor fee, or mail a check with a Form 1040-ES voucher. Keep the confirmation number for each payment — it's your proof of timely payment if the IRS later questions a period.

BACK TO RESOURCES

Tax Planning & Strategy

The Complete Guide to Quarterly Estimated Tax Payments

Self-employed individuals and business owners must pay tax as they earn it, through quarterly estimates. Getting the amount and timing right avoids underpayment penalties and April surprises.

SMAART Tax Team

February 18, 2026

6 min read

|Reviewed by Ray Dominguez, EA, USTCP

The Complete Guide to Quarterly Estimated Tax Payments

Continue Reading

The 2026 Personal Tax Planning Guide Is Here: Every New Number, One Free Download

Tax Planning & Strategy

The Complete Guide to Quarterly Estimated Tax Payments

Related Articles

Continue Reading

The 2026 Personal Tax Planning Guide Is Here: Every New Number, One Free Download

The QBI Deduction: How Pass-Through Businesses Get a 20% Tax Break

2026 Tax Brackets: What Florida Business Owners Need to Know