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Biz Formation Report

Rankings of registered agents, LLC formation and foreign registration services in all 50 states.

Foreign registration report · South Dakota

3 Best Foreign Registration Services in South Dakota (2026)

By the Biz Formation Report editorial team

Biz Formation Report ranks foreign registration services in South Dakota for 2026 as South Dakota Registered Agent.co ($199), Mainstay Filing ($199) and SD Registered Agent.org ($199), in that order. South Dakota Registered Agent.co earns the top grade: the South Dakota registration for $199 with year-one agent service included, then $99 a year.

No.1

Best here

1. South Dakota Registered Agent.co: best for companies adding South Dakota alone

Score9.6out of 10
$199 service fee and the state fee on top; the agent is $99 annually from year two

Top grade, South Dakota Registered Agent.co: $199 beyond the state fee to register in South Dakota, agent renewing at $99.

The plan seats the company at an in-state street address and posts scans of papers served there to your online account.

It beats Mainstay Filing on three-year cost.

What you get

  • Registration prepared and filed
  • The first year as your registered agent

Good

  • $199 service fee, state fee added
  • Registered agent service included for year one
  • $99 a year for the agent from year two

Weak spots

  • Serves South Dakota only; the home state still needs its own agent
  • The EIN application costs $99 extra
Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
Read the South Dakota Registered Agent.co review
No.2

Fifty-state coverage

2. Mainstay Filing: best for companies registered in several states

Score9.1out of 10
$199 service fee, $949 due at checkout with the state fee; the agent is $149 annually from year two

Second grade, Mainstay Filing: $199 added to the state fee in any state, with a year of registered agent service included.

Beyond the free first year, agent service is $149 annually in any state.

South Dakota Registered Agent.co is $100 cheaper across three years, and that difference lowers Mainstay Filing's cost grade.

What you get

  • Registration prepared and filed on your behalf
  • A free first registered agent year
  • Papers served on the company scanned and uploaded the same business day, at no cost

Good

  • $199 service fee plus the state's fee
  • Served papers scanned within the same business day, free
  • Registered agent at no cost in year one
  • One price across all fifty states

Weak spots

  • The agent renews at $149, $50 more than South Dakota Registered Agent.co
Visit Mainstay FilingPartner link. We may earn money if you buy.
Read the Mainstay Filing review
No.3

Lower renewal than Mainstay

3. SD Registered Agent.org: best for registering in South Dakota only

Score8.9out of 10
$199 service fee and the state fee on top; the agent is $99 annually from year two

Third grade, SD Registered Agent.org: $199 beyond the state fee to register in South Dakota, agent renewing at $99.

The plan seats the company at an in-state street address and posts scans of papers served there to your online account.

The two state services, South Dakota Registered Agent.co and SD Registered Agent.org, match on price and features, and the order between them is a narrow call.

What you get

  • Registration prepared and filed
  • The first year as your registered agent

Good

  • $99 annually to keep the agent
  • Includes a year of registered agent service
  • Registers the company at $199 plus filing fees

Weak spots

  • Serves South Dakota only; the home state still needs its own agent
  • The EIN application costs $99 extra
Visit SD Registered Agent.orgPartner link. We may earn money if you buy.
Read the SD Registered Agent.org review

Summary of the 3 grades

RankProviderGradeService feeYear twoBest fitSite
1South Dakota Registered Agent.co9.6$199$99/yrThe lowest agent renewal we rank hereVisit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
2Mainstay Filing9.1$199$149/yrCompanies with a presence in several statesVisit Mainstay FilingPartner link. We may earn money if you buy.
3SD Registered Agent.org8.9$199$99/yrThe lowest agent renewal we rank hereVisit SD Registered Agent.orgPartner link. We may earn money if you buy.

Each grade out of 10 comes from Biz Formation Report's editors and the weighted criteria on How we rank; no customer ratings are involved.

South Dakota foreign registration service prices, 2026: year one, renewal and three-year outlay

ProviderYear 1Year 2Year 3Three-year outlayYear-one agent covered
South Dakota Registered Agent.co$199$99$99$397Included
Mainstay Filing$199$149$149$497Free
SD Registered Agent.org$199$99$99$397Included

All prices were taken from the companies' own websites on November 12, 2026. South Dakota's $750 registration fee is payable on top of each row and is not part of these totals.

What decided the order

Biz Formation Report grades three-year bill and what the money buys at 32% each, leaving 36% for renewal handling, local rules match and pricing openness. In South Dakota, three-year bill settled the order.

Total outlay with South Dakota Registered Agent.co over three years: $397, $100 less than Mainstay Filing. Both providers include the first agent year, so the renewal price set the order.

Every criterion and weight is listed on How we rank.

South Dakota foreign LLC registration: fee, document and filing office

To register, the outside company submits the Application for Certificate of Authority, Foreign Limited Liability Company to the South Dakota Secretary of State, with a state fee of $750. South Dakota also wants certificate of Existence.

After registration the company owes the annual report ($55), due 1st of the anniversary month.

Documents to have on hand

  • Certificate of Existence.
  • The legal name as recorded in the home state, and the date of formation.
  • An in-state registered agent; any provider in this report can serve.
  • Payment of the $750 state fee with the filing.
  • The due date of the annual report and its $55 fee, noted in your calendar.

The cost of skipping South Dakota registration

Its contracts remain enforceable (SDCL 47-34A-1008(b)).

South Dakota foreign registration service: common questions

Must an LLC from another state register with South Dakota?

Yes, as soon as it transacts business there.

How much does South Dakota foreign registration cost?

$750 goes to the state and $199 to the service.

Does South Dakota demand proof of good standing from the home state?

Yes. The filing needs certificate of Existence.

Is a registered agent still needed after foreign registration?

Yes. A registered agent with a street address in the state has to remain on file.

Which foreign registration services does this report rank?

South Dakota Registered Agent.co ($199), Mainstay Filing ($199) and SD Registered Agent.org ($199), in descending order of grade.

What is the best foreign registration service for South Dakota?

South Dakota Registered Agent.co: $199 plus the state fee, one year of registered agent service included, then $99 a year for the agent.

Related pages

Source notes

  1. South Dakota Secretary of State, Business Services / Corporations Division (verified August 2026)
  2. South Dakota Secretary of State, Business Services / Corporations Division (verified August 2026)
  3. South Dakota yearly filing: Annual report: fee and how, official source (verified October 2026)
  4. South Dakota report due date (verified August 2026)
  5. SDCL 47-34A-203 (verified August 2026)
  6. South Dakota formation fee: Filing fee, official source (verified October 2026)
  7. South Dakota formation fee: Filing fee, official source (verified October 2026)
  8. South Dakota registered agent statute (verified October 2026)
  9. South Dakota Secretary of State, business services (verified October 2026)
  10. Foreign LLC application for Certificate of Authority (verified October 2026)
  11. SDCL 47-34A-1003, transacting business (verified October 2026)
  12. SDCL 47-34A-1008, effect of not registering (verified October 2026)
  13. SDCL 47-34A-1001 to 47-34A-1009, foreign limited liability companies (verified November 2026)
  14. Pulled November 12, 2026: South Dakota Registered Agent.co, pricing and service pages
  15. Pulled November 12, 2026: Mainstay Filing, South Dakota service page
  16. Pulled November 12, 2026: SD Registered Agent.org, pricing and service pages