09/04/2026
September can bring important tax deadlines for business owners.
North Dakota’s third-quarter 2026 estimated individual and corporate income tax payments are due September 15, and several monthly sales and use tax filings are due September 30.
South Dakota businesses filing electronically generally have August-period returns due September 21 and payments due September 25.
Consider adding these dates to your calendar and checking with your tax professional or state tax agency to confirm what applies to your business.