What is the sales tax rate in Watertown?
The combined sales tax rate in Watertown, South Dakota is 6.2% as of 2026. It is made up of the South Dakota statewide base rate of 4.2%, plus applicable Codington County and local district taxes. Watertown sits within Codington County, and the rate can vary slightly across ZIP codes because of special district additions (see the ZIP breakdown below).
Sales tax in South Dakota is administered by the South Dakota Department of Revenue, which collects and distributes tax on behalf of the state and its local jurisdictions. The rate applies to most retail sales of tangible personal property delivered within Watertown.
Who needs to collect sales tax in Watertown, South Dakota?
Any business with sales tax nexus in South Dakota must register, collect, and remit sales tax on taxable sales delivered to Watertown. Nexus is established through:
- Physical presence: an office, store, warehouse, employee, or inventory located in South Dakota.
- Economic nexus: exceeding $100,000 in sales to South Dakota customers in the current or prior year.
- Marketplace facilitators: platforms such as Amazon or Etsy collect and remit on behalf of their third-party sellers.
Out-of-state (remote) sellers that cross South Dakota's economic nexus threshold must register with the South Dakota Department of Revenue before continuing to sell into the state.
How do you register for a sales tax permit in Watertown?
To collect sales tax in Watertown, you must register for a sales tax permit with the South Dakota Department of Revenue. Registration is generally free. You will typically need your EIN or SSN, business entity details, bank account information, and an estimate of your monthly South Dakota sales. Most permits are issued within a few business days of an online application.
How do you charge the right sales tax in Watertown?
Sales tax in Watertown is charged based on the delivery address. For orders shipped to a Watertown address, the combined rate of 6.2% generally applies; for in-store sales, the rate is based on the store's location. Because some ZIP codes within Codington County carry additional special-district taxes, always confirm the exact rate for the specific delivery ZIP code. The tables below show the most common Watertown ZIP codes and how Watertown compares with other cities in Codington County and across South Dakota.
