Which state has the lower sales tax nexus threshold, Iowa or South Dakota?

Both Iowa and South Dakota publish the same economic nexus dollar threshold of $100,000, so a remote seller would reach each state's published threshold at the same level of in-state sales. These are the thresholds published by each state's tax authority as of 2026-06-14; confirm against the official source before registering.

Do both Iowa and South Dakota have marketplace facilitator laws?

Yes. Both Iowa and South Dakota have marketplace facilitator laws, so marketplaces such as Amazon, Etsy, and eBay collect and remit sales tax on the sales they facilitate in both states. Direct-to-consumer sales you make outside a marketplace remain your own responsibility once you cross each state's threshold. Verified 2026-06-14.

Which has the lower sales tax rate, Iowa or South Dakota?

South Dakota has the lower combined state and local sales tax rate at 6.10%, compared with 6.94% in Iowa. These are the statewide base rate plus the average local rate; the exact rate depends on the customer's delivery address. As of 2026-06-14.

Do I need to register for sales tax in both Iowa and South Dakota?

It depends on where you cross each state's economic nexus threshold (or have physical presence there). Iowa's published threshold is $100,000, and South Dakota's is $100,000. You generally register in a state only once you cross its threshold, so you may have an obligation in one, both, or neither. Run the nexus calculator with your actual sales and confirm with each state's official source. Thresholds as of 2026-06-14.

When did economic nexus take effect in Iowa and South Dakota?

Iowa's economic nexus rule took effect on 2019-07-01, and South Dakota's took effect on 2023-07-01. Both stem from the 2018 South Dakota v. Wayfair Supreme Court decision, which let states require remote sellers to collect once an economic threshold is met.

Iowa vs South Dakota Sales Tax: 6.94% vs 6.10%, Nexus 2026

Updated 2026-06-26

Reviewed by Nexus by State research team using official state tax sources. Last reviewed 2026-06-26.

Compare Iowa and South Dakota sales tax rates: Iowa shows a 6.94% combined state and average local rate with a $100,000 economic nexus threshold, while South Dakota shows 6.10% with a $100,000 threshold. This guide focuses on seller sales-tax obligations rather than personal income-tax returns.

Metric	Iowa	South Dakota
Economic nexus threshold	$100,000	$100,000
Transaction threshold	None	None
State rate	6.00%	4.20%
Avg. local rate	0.94%	1.90%
Combined state + local	6.94%	6.10%
Marketplace facilitator	Yes	Yes
Effective since	2019-07-01	2023-07-01

Which state is easier for sellers?

For low-revenue sellers: nexus triggers first in both states because of its threshold. If you cross that first, you register there first.

On rate: South Dakota is friendlier for customers with a combined state + local rate of 6.10% vs 6.94%.

Neither state has a transaction-count trigger — only the dollar threshold matters.

Iowa — nexus note

Iowa sales/use tax nexus and economic nexus threshold: a remote seller or marketplace facilitator must register, collect, and remit Iowa sales tax only if its gross revenue from Iowa sales is $100,000 or more in a calendar year. Iowa originally enacted a $100,000-or-200-transaction test effective January 1, 2019 (Senate File 2417) but eliminated the 200-transaction threshold effective July 1, 2019 (House File 779), so the current trigger is sales-only. The $100,000 figure counts all Iowa revenue, including exempt sales, wholesale sales, sales for resale, and sales for which a marketplace facilitator collected the tax. Marketplace facilitators meeting the threshold collect and remit on behalf of their marketplace sellers. Iowa imposes a 6% state sales tax plus a 1% local option sales tax in most jurisdictions. Iowa Department of Revenue source data last retrieved 2026-06-14.

South Dakota — nexus note

South Dakota sales tax nexus and economic nexus threshold: a remote seller must register and collect South Dakota sales tax once gross sales delivered into South Dakota exceed $100,000 in the previous or current calendar year. South Dakota — the state behind South Dakota v. Wayfair — eliminated its original 200-separate-transaction test effective July 1, 2023 under Senate Bill 30, so the trigger is now sales-only with no transaction count. Marketplace facilitators (Amazon, eBay, Etsy, Walmart) with more than $100,000 in South Dakota sales must collect and remit on facilitated sales, and sales made through a marketplace still count toward a remote seller's own $100,000 threshold even when the marketplace already collects the tax. South Dakota imposes a 4.2% statewide sales/use tax plus municipal sales taxes. South Dakota Department of Revenue source data last retrieved 2026-06-14.

What to do next

Use the nexus calculator to check exactly which of Iowa and South Dakota you've already triggered. Then read each state's full guide:

Iowa overview →South Dakota overview →

Frequently asked questions

Which state has the lower sales tax nexus threshold, Iowa or South Dakota?: Both Iowa and South Dakota publish the same economic nexus dollar threshold of $100,000, so a remote seller would reach each state's published threshold at the same level of in-state sales. These are the thresholds published by each state's tax authority as of 2026-06-14; confirm against the official source before registering.
Do both Iowa and South Dakota have marketplace facilitator laws?: Yes. Both Iowa and South Dakota have marketplace facilitator laws, so marketplaces such as Amazon, Etsy, and eBay collect and remit sales tax on the sales they facilitate in both states. Direct-to-consumer sales you make outside a marketplace remain your own responsibility once you cross each state's threshold. Verified 2026-06-14.
Which has the lower sales tax rate, Iowa or South Dakota?: South Dakota has the lower combined state and local sales tax rate at 6.10%, compared with 6.94% in Iowa. These are the statewide base rate plus the average local rate; the exact rate depends on the customer's delivery address. As of 2026-06-14.
Do I need to register for sales tax in both Iowa and South Dakota?: It depends on where you cross each state's economic nexus threshold (or have physical presence there). Iowa's published threshold is $100,000, and South Dakota's is $100,000. You generally register in a state only once you cross its threshold, so you may have an obligation in one, both, or neither. Run the nexus calculator with your actual sales and confirm with each state's official source. Thresholds as of 2026-06-14.
When did economic nexus take effect in Iowa and South Dakota?: Iowa's economic nexus rule took effect on 2019-07-01, and South Dakota's took effect on 2023-07-01. Both stem from the 2018 South Dakota v. Wayfair Supreme Court decision, which let states require remote sellers to collect once an economic threshold is met.

More sales tax comparisons

Selling into more than two states? Compare Iowa and South Dakota against other major markets for nexus thresholds, rates, and marketplace facilitator rules.

More Iowa comparisons

More South Dakota comparisons

Sources

date_retrieved: Iowa 2026-06-14 · South Dakota 2026-06-14

Iowa: https://tax.iowa.gov/
Iowa: https://revenue.iowa.gov/taxes/tax-guidance/sales-use-excise-tax/remote-sellers-marketplace-facilitators
Iowa: https://www.salestaxinstitute.com/resources/economic-nexus-state-guide
Iowa: https://taxfoundation.org/data/all/state/sales-tax-rates/
South Dakota: https://dor.sd.gov/
South Dakota: https://dor.sd.gov/businesses/taxes/sales-use-tax/
South Dakota: https://www.salestaxinstitute.com/resources/economic-nexus-state-guide
South Dakota: https://taxfoundation.org/data/all/state/sales-tax-rates/