The South Dakota R&D tax credit, explained
No, South Dakota has no state R&D tax credit because it has no corporate or personal income tax at all.
Last verified July 2026 against South Dakota Department of Revenue guidance.
The short answer
Does South Dakota have an R&D tax credit? No. South Dakota does not levy a corporate income tax or a personal income tax, so there is no state income tax liability for a research credit to offset in the first place.
Where that leaves South Dakota startups
This is different from most no-credit states, where an income tax exists but lawmakers simply chose not to pass an R&D credit. In South Dakota, the tax itself does not exist, which the Department of Revenue's business tax listing confirms by omission: it covers sales and use tax, contractor's excise tax, and bank franchise tax, with no income tax line at all.
For companies doing research in South Dakota, the federal R&D credit is the only R&D-specific tax benefit available, and it applies in full regardless of the state's tax structure.
How it stacks with the federal credit
Since there is no state credit to stack, the full value of a South Dakota company's R&D benefit comes from the federal credit, worth roughly 6% to 10% of qualified research spend. Startups under $5 million in revenue can apply up to $500,000 of it against payroll taxes each year.
Example: a Sioux Falls agtech startup with 11 employees and $980,000 in qualified research wages and supplies could see a federal credit near $69,000 at a 7% effective rate. As a qualifying startup, the company could apply that directly against its payroll tax deposits rather than waiting on income tax liability that may not exist yet.
Some founders assume South Dakota's lack of income tax also means no R&D benefit at all. That is not the case. The federal credit runs through the federal return and the payroll tax system, both of which apply the same way in South Dakota as anywhere else.
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Claiming the federal credit instead
Because there is no South Dakota income tax, there is no state form to file and nothing for a company's CPA to claim at the state level for R&D specifically.
The federal credit is claimed on Form 6765 with the company's federal return. Claimship prepares that study and package; the company's CPA files the federal return and handles South Dakota's other business tax obligations, like sales and use tax, separately.
Any South Dakota company doing qualifying product, software, or process development work can pursue the federal credit the same way a company in any other state would.
Official source: South Dakota Department of Revenue.
Carryforward and deadlines
There are no state carryforward rules or filing deadlines to track for an R&D credit in South Dakota, since none exists.
Federal carryforward rules apply as usual: unused federal credit generally carries forward up to 20 years, and the payroll tax election has its own annual timing tied to the federal return.