South Dakota Quarterly Tax Calculator 2026

If you are self-employed, a freelancer, or have significant income not subject to withholding in South Dakota, you are likely required to make quarterly estimated tax payments. The federal quarterly due dates are April 15, June 15, September 15, and January 15 (of the following year).

Because South Dakota has no state income tax, your quarterly payments only need to cover federal obligations: federal income tax and self-employment tax (if applicable). This simplifies your quarterly filing process since you do not need to make separate state estimated payments. You can use IRS Form 1040-ES to calculate and submit your federal quarterly payments.

To avoid underpayment penalties, aim to pay at least 90% of your current year tax liability or 100% of your prior year tax liability (110% if your AGI exceeded $150,000). The calculator above compares both methods and recommends the lower amount.

Remember that quarterly payments are cumulative. If you underpay one quarter, you can increase payments in subsequent quarters. However, you may still incur a small penalty for the quarter you underpaid.